WorldWideScience

Sample records for surface cover called

  1. 26 CFR 1.1092(c)-1 - Qualified covered calls.

    Science.gov (United States)

    2010-04-01

    ... lowest qualified benchmark is determined using the adjusted applicable stock price, as defined in § 1... (CONTINUED) INCOME TAXES Wash Sales of Stock Or Securities § 1.1092(c)-1 Qualified covered calls. (a) In.... Under section 1092(d)(3)(B)(i)(I), stock is personal property if the stock is part of a straddle that...

  2. Systematic approach to designing surface covers for uranium-mill tailings

    International Nuclear Information System (INIS)

    Beedlow, P.A.; Cadwell, L.L.; McShane, M.C.

    1982-01-01

    The wide range of environmental conditions present at uranium mill tailings sites precludes the use of a single type of surface cover. Surface covers must be designed on a site-specific basis. To facilitate site specific designs the UMTRA program is developing guidelines for designing surface covers. This paper presents a systematic approach to designing surface covers for tailings that can be applied under any site condition. The approach consists of three phases: (1) An assessment during which the degree of surface protection is determined. (2) A preliminary design that facilitates interaction with those designing other containment system elements. (3) A final design where the cost and effectiveness of the surface cover are determined. The types of information required to apply this approach are discussed

  3. Design surface covers: an approach to long-term waste site stabilization

    International Nuclear Information System (INIS)

    Beedlow, P.A.; Cadwell, L.L.; McShane, M.C.

    1983-02-01

    The wide range of existing environmental conditions, potential contaminants and available cover materials at waste disposal sites necessitates site-specific designing of surface covers for effective long-term erosion resistance. This paper presents a systematic approach to designing surface covers for hazardous waste repositories that can be tailored to conditions at any site. The approach consists of three phases: (1) an assessment, during which the degree of required surface protection (erosion potential) is determined; (2) a preliminary design that integrates surface cover design with the need to minimize transport of contaminants; and (3) a final design, where the cost and effectiveness of the surface cover are determined. 1 figure

  4. Uncertainty in Land Cover observations and its impact on near surface climate

    Science.gov (United States)

    Georgievski, Goran; Hagemann, Stefan

    2017-04-01

    Land Cover (LC) and its bio-geo-physical feedbacks are important for the understanding of climate and its vulnerability to changes on the surface of the Earth. Recently ESA has published a new LC map derived by combining remotely sensed surface reflectance and ground-truth observations. For each grid-box at 300m resolution, an estimate of confidence is provided. This LC data set can be used in climate modelling to derive land surface boundary parameters for the respective Land Surface Model (LSM). However, the ESA LC classes are not directly suitable for LSMs, therefore they need to be converted into the model specific surface presentations. Due to different design and processes implemented in various climate models they might differ in the treatment of artificial, water bodies, ice, bare or vegetated surfaces. Nevertheless, usually vegetation distribution in models is presented by means of plant functional types (PFT), which is a classification system used to simplify vegetation representation and group different vegetation types according to their biophysical characteristics. The method of LC conversion into PFT is also called "cross-walking" (CW) procedure. The CW procedure is another source of uncertainty, since it depends on model design and processes implemented and resolved by LSMs. These two sources of uncertainty, (i) due to surface reflectance conversion into LC classes, (ii) due to CW procedure, have been studied by Hartley et al (2016) to investigate their impact on LSM state variables (albedo, evapotranspiration (ET) and primary productivity) by using three standalone LSMs. The present study is a follow up to that work and aims at quantifying the impact of these two uncertainties on climate simulations performed with the Max Planck Institute for Meteorology Earth System Model (MPI-ESM) using prescribed sea surface temperature and sea ice. The main focus is on the terrestrial water cycle, but the impacts on surface albedo, wind patterns, 2m temperatures

  5. The seasonal cycle of snow cover, sea ice and surface albedo

    Science.gov (United States)

    Robock, A.

    1980-01-01

    The paper examines satellite data used to construct mean snow cover caps for the Northern Hemisphere. The zonally averaged snow cover from these maps is used to calculate the seasonal cycle of zonally averaged surface albedo. The effects of meltwater on the surface, solar zenith angle, and cloudiness are parameterized and included in the calculations of snow and ice albedo. The data allows a calculation of surface albedo for any land or ocean 10 deg latitude band as a function of surface temperature ice and snow cover; the correct determination of the ice boundary is more important than the snow boundary for accurately simulating the ice and snow albedo feedback.

  6. Superhydrophilicity of a nanofiber-covered aluminum surface fabricated via pyrophosphoric acid anodizing

    Science.gov (United States)

    Nakajima, Daiki; Kikuchi, Tatsuya; Natsui, Shungo; Suzuki, Ryosuke O.

    2016-12-01

    A superhydrophilic aluminum surface covered by numerous alumina nanofibers was fabricated via pyrophosphoric acid anodizing. High-density anodic alumina nanofibers grow on the bottom of a honeycomb oxide via anodizing in concentrated pyrophosphoric acid. The water contact angle on the nanofiber-covered aluminum surface decreased with time after a 4 μL droplet was placed on the surface, and a superhydrophilic behavior with a contact angle measuring 2.2° was observed within 2 s; this contact angle is considerably lower than those observed for electropolished and porous alumina-covered aluminum surfaces. There was no dependence of the superhydrophilicity on the density of alumina nanofibers fabricated via different constant voltage anodizing conditions. The superhydrophilic property of the surface covered by anodic alumina nanofibers was maintained during an exposure test for 359 h. The quick-drying and snow-sliding behaviors of the superhydrophilic aluminum covered with anodic alumina nanofibers were demonstrated.

  7. Temporal Changes in the Observed Relationship between Cloud Cover and Surface Air Temperature.

    Science.gov (United States)

    Sun, Bomin; Groisman, Pavel Ya.; Bradley, Raymond S.; Keimig, Frank T.

    2000-12-01

    The relationship between cloud cover and near-surface air temperature and its decadal changes are examined using the hourly synoptic data for the past four to six decades from five regions of the Northern Hemisphere: Canada, the United States, the former Soviet Union, China, and tropical islands of the western Pacific. The authors define the normalized cloud cover-surface air temperature relationship, NOCET or dT/dCL, as a temperature anomaly with a unit (one-tenth) deviation of total cloud cover from its average value. Then mean monthly NOCET time series (night- and daytime, separately) are area-averaged and parameterized as functions of surface air humidity and snow cover. The day- and nighttime NOCET variations are strongly anticorrelated with changes in surface humidity. Furthermore, the daytime NOCET changes are positively correlated to changes in snow cover extent. The regionally averaged nighttime NOCET varies from 0.05 K tenth1 in the wet Tropics to 1.0 K tenth1 at midlatitudes in winter. The daytime regional NOCET ranges from 0.4 K tenth1 in the Tropics to 0.7 K tenth1 at midlatitudes in winter.The authors found a general strengthening of a daytime surface cooling during the post-World War II period associated with cloud cover over the United States and China, but a minor reduction of this cooling in higher latitudes. Furthermore, since the 1970s, a prominent increase in atmospheric humidity has significantly weakened the effectiveness of the surface warming (best seen at nighttime) associated with cloud cover.The authors apportion the spatiotemporal field of interactions between total cloud cover and surface air temperature into a bivariate relationship (described by two equations, one for daytime and one for nighttime) with surface air humidity and snow cover and two constant factors. These factors are invariant in space and time domains. It is speculated that they may represent empirical estimates of the overall cloud cover effect on the surface air

  8. Thermal Advantages for Solar Heating Systems with a Glass Cover with Antireflection Surfaces

    DEFF Research Database (Denmark)

    Furbo, Simon; Shah, Louise Jivan

    2003-01-01

    Investigations elucidate how a glass cover with antireflection surfaces can improve the efficiency of a solar collector and the thermal performance of solar heating systems. The transmittances for two glass covers for a flat-plate solar collector were measured for different incidence angles....... The two glasses are identical, except for the fact that one of them is equipped with antireflection surfaces by the company SunArc A/ S. The transmittance was increased by 5–9%-points due to the antireflection surfaces. The increase depends on the incidence angle. The efficiency at incidence angles of 08...... and the incidence angle modifier were measured for a flat-plate solar collector with the two cover plates. The collector efficiency was increased by 4–6%-points due to the antireflection surfaces, depending on the incidence angle. The thermal advantage with using a glass cover with antireflection surfaces...

  9. Effects of Surface Roughness and Mechanical Properties of Cover-Layer on Near-Field Optical Recording

    Science.gov (United States)

    Kim, Jin-Hong; Lee, Jun-Seok; Lim, Jungshik; Seo, Jung-Kyo

    2009-03-01

    Narrow gap distance in cover-layer incident near-field recording (NFR) configuration causes a collision problem in the interface between a solid immersion lens and a disk surface. A polymer cover-layer with smooth surface results in a stable gap servo while a nanocomposite cover-layer with high refractive index shows a collision problem during the gap servo test. Even though a dielectric cover-layer, in which the surface is rougher than the polymer, supplements the mechanical properties, an unclear eye pattern due to an unstable gap servo can be obtained after a chemical mechanical polishing. Not only smooth surface but also good mechanical properties of cover-layer are required for the stable gap servo in the NFR.

  10. GLOBAL LAND COVER CLASSIFICATION USING MODIS SURFACE REFLECTANCE PROSUCTS

    Directory of Open Access Journals (Sweden)

    K. Fukue

    2016-06-01

    Full Text Available The objective of this study is to develop high accuracy land cover classification algorithm for Global scale by using multi-temporal MODIS land reflectance products. In this study, time-domain co-occurrence matrix was introduced as a classification feature which provides time-series signature of land covers. Further, the non-parametric minimum distance classifier was introduced for timedomain co-occurrence matrix, which performs multi-dimensional pattern matching for time-domain co-occurrence matrices of a classification target pixel and each classification classes. The global land cover classification experiments have been conducted by applying the proposed classification method using 46 multi-temporal(in one year SR(Surface Reflectance and NBAR(Nadir BRDF-Adjusted Reflectance products, respectively. IGBP 17 land cover categories were used in our classification experiments. As the results, SR and NBAR products showed similar classification accuracy of 99%.

  11. Impacts of land cover transitions on surface temperature in China based on satellite observations

    Science.gov (United States)

    Zhang, Yuzhen; Liang, Shunlin

    2018-02-01

    China has experienced intense land use and land cover changes during the past several decades, which have exerted significant influences on climate change. Previous studies exploring related climatic effects have focused mainly on one or two specific land use changes, or have considered all land use and land cover change types together without distinguishing their individual impacts, and few have examined the physical processes of the mechanism through which land use changes affect surface temperature. However, in this study, we considered satellite-derived data of multiple land cover changes and transitions in China. The objective was to obtain observational evidence of the climatic effects of land cover transitions in China by exploring how they affect surface temperature and to what degree they influence it through the modification of biophysical processes, with an emphasis on changes in surface albedo and evapotranspiration (ET). To achieve this goal, we quantified the changes in albedo, ET, and surface temperature in the transition areas, examined their correlations with temperature change, and calculated the contributions of different land use transitions to surface temperature change via changes in albedo and ET. Results suggested that land cover transitions from cropland to urban land increased land surface temperature (LST) during both daytime and nighttime by 0.18 and 0.01 K, respectively. Conversely, the transition of forest to cropland tended to decrease surface temperature by 0.53 K during the day and by 0.07 K at night, mainly through changes in surface albedo. Decreases in both daytime and nighttime LST were observed over regions of grassland to forest transition, corresponding to average values of 0.44 and 0.20 K, respectively, predominantly controlled by changes in ET. These results highlight the necessity to consider the individual climatic effects of different land cover transitions or conversions in climate research studies. This short

  12. Surface runoff generation in a small watershed covered by sugarcane and riparian forest

    Directory of Open Access Journals (Sweden)

    Rafael Pires Fernandes

    2013-12-01

    Full Text Available Since an understanding of how runoff is generated is of great importance to soil conservation, to water availability and to the management of a watershed, the objective of this study was to understand the generation of surface runoff in a watershed covered by sugarcane and riparian forest. Nine surface runoff plots were set up, evenly distributed on the lower, middle and upper slopes. The lower portion was covered by riparian forest. We showed that the average surface runoff coefficient along the slope in the present study was higher than in other studies under different land uses. Furthermore, the surface runoff was higher under sugarcane compared to the riparian forest, especially after sugarcane harvesting. Besides land cover, other factors such as the characteristics of rainfall events, relief and physical soil characteristics such as soil bulk density and saturated hydraulic conductivity influenced the surface runoff generation.

  13. Study on mechanics of driving drum with superelastic convexity surface covering-layer structure

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, L.J.; Sui, X.H.; Miao, D.J. [Shandong University of Science & Technology, Qingdao (China)

    2008-09-15

    Belt conveyor is one of the main transport equipment in coal mine and the driving drum is its key part. With the method of bionic design, the mushroom morphological structure is applied to the design of covering-layer structure of driving drum surface of belt conveyor. Superelastic rubber with large deformation is adopted as the covering-layer material. Nonlinear constitutive model of rubber, which is of superelasticity and large deformation, is established. The stress states and deformation principles of driving drums including both bionic covering-layer and common covering-layer are obtained by static intensity analysis with Finite Element Analysis (FEA) software ANSYS. The values of the stress and strain on the driving drum surface are gotten and the dangerous area is determined. FEA results show that the superelastic convexity surface structure can enlarge the contact area between the driving drum and viscoelastic belt. The results also show that in comparison with common driving drum, the bionic surface driving drum can not only increase the friction coefficient between drum and belt but also prolong its service life.

  14. Use of AMSR-E microwave satellite data for land surface characteristics and snow cover variation

    Directory of Open Access Journals (Sweden)

    Mukesh Singh Boori

    2016-12-01

    Full Text Available This data article contains data related to the research article entitled “Global land cover classification based on microwave polarization and gradient ratio (MPGR” [1] and “Microwave polarization and gradient ratio (MPGR for global land surface phenology” [2]. This data article presents land surface characteristics and snow cover variation information from sensors like EOS Advanced Microwave Scanning Radiometer (AMSR-E. This data article use the HDF Explorer, Matlab, and ArcGIS software to process the pixel latitude, longitude, snow water equivalent (SWE, digital elevation model (DEM and Brightness Temperature (BT information from AMSR-E satellite data to provide land surface characteristics and snow cover variation data in all-weather condition at any time. This data information is useful to discriminate different land surface cover types and snow cover variation, which is turn, will help to improve monitoring of weather, climate and natural disasters.

  15. GLOBAL CHANGES IN THE SEA ICE COVER AND ASSOCIATED SURFACE TEMPERATURE CHANGES

    Directory of Open Access Journals (Sweden)

    J. C. Comiso

    2016-06-01

    Full Text Available The trends in the sea ice cover in the two hemispheres have been observed to be asymmetric with the rate of change in the Arctic being negative at −3.8 % per decade while that of the Antarctic is positive at 1.7 % per decade. These observations are confirmed in this study through analyses of a more robust data set that has been enhanced for better consistency and updated for improved statistics. With reports of anthropogenic global warming such phenomenon appears physically counter intuitive but trend studies of surface temperature over the same time period show the occurrence of a similar asymmetry. Satellite surface temperature data show that while global warming is strong and dominant in the Arctic, it is relatively minor in the Antarctic with the trends in sea ice covered areas and surrounding ice free regions observed to be even negative. A strong correlation of ice extent with surface temperature is observed, especially during the growth season, and the observed trends in the sea ice cover are coherent with the trends in surface temperature. The trend of global averages of the ice cover is negative but modest and is consistent and compatible with the positive but modest trend in global surface temperature. A continuation of the trend would mean the disappearance of summer ice by the end of the century but modelling projections indicate that the summer ice could be salvaged if anthropogenic greenhouse gases in the atmosphere are kept constant at the current level.

  16. The relationship of post-fire white ash cover to surface fuel consumption

    Science.gov (United States)

    Andrew T. Hudak; Roger D. Ottmar; Robert E. Vihnanek; Nolan W. Brewer; Alistair M. S. Smith; Penelope Morgan

    2013-01-01

    White ash results from the complete combustion of surface fuels, making it a logically simple retrospective indicator of surface fuel consumption. However, the strength of this relationship has been neither tested nor adequately demonstrated with field measurements. We measured surface fuel loads and cover fractions of white ash and four other surface materials (green...

  17. Effects of shrub and tree cover increase on the near-surface atmosphere in northern Fennoscandia

    Directory of Open Access Journals (Sweden)

    J. H. Rydsaa

    2017-09-01

    Full Text Available Increased shrub and tree cover in high latitudes is a widely observed response to climate change that can lead to positive feedbacks to the regional climate. In this study we evaluate the sensitivity of the near-surface atmosphere to a potential increase in shrub and tree cover in the northern Fennoscandia region. We have applied the Weather Research and Forecasting (WRF model with the Noah-UA land surface module in evaluating biophysical effects of increased shrub cover on the near-surface atmosphere at a fine resolution (5.4 km  ×  5.4 km. Perturbation experiments are performed in which we prescribe a gradual increase in taller vegetation in the alpine shrub and tree cover according to empirically established bioclimatic zones within the study region. We focus on the spring and summer atmospheric response. To evaluate the sensitivity of the atmospheric response to inter-annual variability in climate, simulations were conducted for two contrasting years, one warm and one cold. We find that shrub and tree cover increase leads to a general increase in near-surface temperatures, with the highest influence seen during the snowmelt season and a more moderate effect during summer. We find that the warming effect is stronger in taller vegetation types, with more complex canopies leading to decreases in the surface albedo. Counteracting effects include increased evapotranspiration, which can lead to increased cloud cover, precipitation, and snow cover. We find that the strength of the atmospheric feedback is sensitive to snow cover variations and to a lesser extent to summer temperatures. Our results show that the positive feedback to high-latitude warming induced by increased shrub and tree cover is a robust feature across inter-annual differences in meteorological conditions and will likely play an important role in land–atmosphere feedback processes in the future.

  18. Functional levels of floor surface roughness for the prevention of slips and falls: clean-and-dry and soapsuds-covered wet surfaces.

    Science.gov (United States)

    Kim, In-Ju; Hsiao, Hongwei; Simeonov, Peter

    2013-01-01

    Literature has shown a general trend that slip resistance performance improves with floor surface roughness. However, whether slip resistance properties are linearly correlated with surface topographies of the floors or what roughness levels are required for effective slip resistance performance still remain to be answered. This pilot study aimed to investigate slip resistance properties and identify functional levels of floor surface roughness for practical design applications in reducing the risk of slip and fall incidents. A theory model was proposed to characterize functional levels of surface roughness of floor surfaces by introducing a new concept of three distinctive zones. A series of dynamic friction tests were conducted using 3 shoes and 9 floor specimens under clean-and-dry as well as soapsuds-covered slippery wet environments. The results showed that all the tested floor-shoe combinations provided sufficient slip resistances performance under the clean-and-dry condition. A significant effect of floor type (surface roughness) on dynamic friction coefficient (DFC) was found in the soapsuds-covered wet condition. As compared to the surface roughness effects, the shoe-type effects were relatively small. Under the soapsuds-covered wet condition, floors with 50 μm in Ra roughness scale seemed to represent an upper bound in the functional range of floor surface roughness for slip resistance because further increase of surface roughness provided no additional benefit. A lower bound of the functional range for slip resistance under the soapsuds-covered wet condition was estimated from the requirement of DFC > 0.4 at Ra ≅ 17 μm. Findings from this study may have potential safety implications in the floor surface design for reducing slip and fall hazards. Published by Elsevier Ltd.

  19. The role of surface energy fluxes in pan-Arctic snow cover changes

    International Nuclear Information System (INIS)

    Shi Xiaogang; Lettenmaier, Dennis P; Groisman, Pavel Ya; Dery, Stephen J

    2011-01-01

    We analyze snow cover extent (SCE) trends in the National Oceanic and Atmospheric Administration's (NOAA) northern hemisphere weekly satellite SCE data using the Mann-Kendall trend test and find that North American and Eurasian snow cover in the pan-Arctic have declined significantly in spring and summer over the period of satellite record beginning in the early 1970s. These trends are reproduced, both in trend direction and statistical significance, in reconstructions using the variable infiltration capacity (VIC) hydrological model. We find that spring and summer surface radiative and turbulent fluxes generated in VIC have strong correlations with satellite observations of SCE. We identify the role of surface energy fluxes and determine which is most responsible for the observed spring and summer SCE recession. We find that positive trends in surface net radiation (SNR) accompany most of the SCE trends, whereas modeled latent heat (LH) and sensible heat (SH) trends associated with warming on SCE mostly cancel each other, except for North America in spring, and to a lesser extent for Eurasia in summer. In spring over North America and summer in Eurasia, the SH contribution to the observed snow cover trends is substantial. The results indicate that ΔSNR is the primary energy source and ΔSH plays a secondary role in changes of SCE. Compared with ΔSNR and ΔSH, ΔLH has a minor influence on pan-Arctic snow cover changes.

  20. Mobbing call experiment suggests the enhancement of forest bird movement by tree cover in urban landscapes across seasons

    Directory of Open Access Journals (Sweden)

    Atsushi Shimazaki

    2017-06-01

    Full Text Available Local scale movement behavior is an important basis to predict large-scale bird movements in heterogeneous landscapes. Here we conducted playback experiments using mobbing calls to estimate the probability that forest birds would cross a 50-m urban area during three seasons (breeding, dispersal, and wintering seasons with varying amounts of tree cover, building area, and electric wire density. We examined the responses of four forest resident species: Marsh Tit (Poecile palustris, Varied Tit (Sittiparus varius, Japanese Tit (P. minor, and Eurasian Nuthatch (Sitta europaea in central Hokkaido, northern Japan. We carried out and analyzed 250 playback experiments that attracted 618 individuals. Our results showed that tree cover increased the crossing probability of three species other than Varied Tit. Building area and electric wire density had no detectable effect on crossing probability for four species. Seasonal difference in the crossing probability was found only for Varied Tit, and the probability was the highest in the breeding season. These results suggest that the positive effect of tree cover on the crossing probability would be consistent across seasons. We therefore conclude that planting trees would be an effective way to promote forest bird movement within an urban landscape.

  1. Surface treatment systems for concrete in marine environment: Effect of concrete cover thickness

    Directory of Open Access Journals (Sweden)

    Marcelo Henrique Farias de Medeiros

    Full Text Available Abstract There are some ways to extend the service life of a reinforced concrete structure. This paper focuses on the extension of the service life by treating the surface of reinforced concrete, specifically on the effect of the concrete cover thickness on the surface treatment system efficacy. Thus, chloride migration tests were performed and diffusion chloride coefficients were calculated. The service life of each case (treated or non-treated concrete was estimated using these data and Fick's second law of diffusion. Results indicated that the thicker the concrete cover is, the greater the efficacy of the concrete surface treatment system will be. The dissemination of this information is important, since it is almost intuitive to think that the effect of a surface treatment system depends only on itself and this study shows the opposite.

  2. Emissivity Measurements of Foam-Covered Water Surface at L-Band for Low Water Temperatures

    Directory of Open Access Journals (Sweden)

    En-Bo Wei

    2014-11-01

    Full Text Available For a foam-covered sea surface, it is difficult to retrieve sea surface salinity (SSS with L-band brightness temperature (1.4 GHz because of the effect of a foam layer with wind speeds stronger than 7 m/s, especially at low sea surface temperature (SST. With foam-controlled experiments, emissivities of a foam-covered water surface at low SST (−1.4 °C to 1.7 °C are measured for varying SSS, foam thickness, incidence angle, and polarization. Furthermore, a theoretical model of emissivity is introduced by combining wave approach theory with the effective medium approximation method. Good agreement is obtained upon comparing theoretical emissivities with those of experiments. The results indicate that foam parameters have a strong influence on increasing emissivity of a foam-covered water surface. Increments of experimental emissivities caused by foam thickness of 1 cm increase from about 0.014 to 0.131 for horizontal polarization and 0.022 to 0.150 for vertical polarization with SSS increase and SST decrease. Contributions of the interface between the foam layer and water surface to the foam layer emissivity increments are discussed for frequencies between 1 and 37 GHz.

  3. Mapping surface temperature variability on a debris-covered glacier with an unmanned aerial vehicle

    Science.gov (United States)

    Kraaijenbrink, P. D. A.; Litt, M.; Shea, J. M.; Treichler, D.; Koch, I.; Immerzeel, W.

    2016-12-01

    Debris-covered glacier tongues cover about 12% of the glacier surface in high mountain Asia and much of the melt water is generated from those glaciers. A thin layer of supraglacial debris enhances ice melt by lowering the albedo, while thicker debris insulates the ice and reduces melt. Data on debris thickness is therefore an important input for energy balance modelling of these glaciers. Thermal infrared remote sensing can be used to estimate the debris thickness by using an inverse relation between debris surface temperature and thickness. To date this has only been performed using coarse spaceborne thermal imagery, which cannot reveal small scale variation in debris thickness and its influence on the heterogeneous melt patterns on debris-covered glaciers. We deployed an unmanned aerial vehicle mounted with a thermal infrared sensor over the debris-covered Lirung Glacier in Nepal three times in May 2016 to reveal the spatial and temporal variability of surface temperature in high detail. The UAV survey matched a Landsat 8 overpass to be able to make a comparison with spaceborne thermal imagery. The UAV-acquired data is processed using Structure from Motion photogrammetry and georeferenced using DGPS-measured ground control points. Different surface types were distinguished by using data acquired by an additional optical UAV survey in order to correct for differences in surface emissivity. In situ temperature measurements and incoming solar radiation data are used to calibrate the temperature calculations. Debris thicknesses derived are validated by thickness measurements of a ground penetrating radar. Preliminary analysis reveals a spatially highly heterogeneous pattern of surface temperature over Lirung Glacier with a range in temperature of over 40 K. At dawn the debris is relatively cold and its temperature is influenced strongly by the ice underneath. Exposed to the high solar radiation at the high altitude the debris layer heats up very rapidly as sunrise

  4. Surface energy balance of seasonal snow cover for snow-melt ...

    Indian Academy of Sciences (India)

    This study describes time series analysis of snow-melt, radiation data and energy balance for a seasonal snow cover at Dhundi field station of SASE, which lies in Pir Panjal range of the. N–W Himalaya, for a winter season from 13 January to 12 April 2005. The analysis shows that mean snow surface temperature remains ...

  5. Electromagnetic Scattering from Rough Sea Surface with PM Spectrum Covered by an Organic Film

    International Nuclear Information System (INIS)

    Wang Rui; Guo Li-Xin; Wang An-Qi; Wu Zhen-Sen

    2011-01-01

    The rough sea surface covered by an organic film will cause attenuation of capillarity waves, which implies that the organic films play an important role in rough sea surface processes. We focus on a one-dimensional (1D) rough sea surface with the Pierson—Moskowitz (PM) spectrum distributed to the homogeneous insoluble organic slicks. First, the impact of the organic film on the PM surface spectrum is presented, as well as that of the correlation length, the rms height and slope of the rough sea surface. The damping effect of the organic film changes the physical parameters of the rough sea surface. For example, the organic film will reduce the rms height and slopee of the rough sea surface, which results in the attenuation of the high-frequency components of the PM spectrum leading to modification of the surface PM spectrum. Then, the influence of the organic film on the electromagnetic (EM) scattering coefficients from PM rough sea surface covered by the organic film is investigated and discussed in detail, compared with the clean PM rough sea surface through the method of moments. (fundamental areas of phenomenology(including applications))

  6. Surface albedo in different land-use and cover types in Amazon forest region

    Directory of Open Access Journals (Sweden)

    Thiago de Oliveira Faria

    2018-05-01

    Full Text Available Albedo is the portion of energy from the Sun that is reflected by the earth's surface, thus being an important variable that controls climate and energy processes on Earth. Surface albedo is directly related to the characteristics of the Earth’s surface materials, making it a useful parameter to evaluate the effects of original soil cover replacement due to human occupation. This study evaluated the changes in the surface albedo values due to the conversion of vegetation to other land uses and to analyze the applicability of the use of albedo in the spatial delimitation of land-use classes in the transitional region between the Cerrado and Amazon biomes. Surface albedo measurements were obtained from processing of Landsat Thematic Mapper data in the Geographic Information System (GIS, and land-use information were collected using Google Earth high-resolution images. The results show that human activities such as the cultivation of crops and burning have contributed substantially to variations in the surface albedo, and that albedo estimates from Landsat imagery have the potential to help in the recognition and delimitation of features of land use and cover.

  7. Surfacing behavior and gas release of the physostome sprat (Sprattus sprattus) in ice-free and ice-covered waters

    KAUST Repository

    Solberg, Ingrid

    2013-10-04

    Upward-facing echosounders that provided continuous, long-term measurements were applied to address the surfacing behavior and gas release of the physostome sprat (Sprattus sprattus) throughout an entire winter in a 150-m-deep Norwegian fjord. During ice-free conditions, the sprat surfaced and released gas bubbles at night with an estimated surfacing rate of 3.5 times per fish day-1. The vertical swimming speeds during surfacing were considerably higher (~10 times) than during diel vertical migrations, especially when returning from the surface, and particularly when the fjord was not ice covered. The sprat released gas a few hours after surfacing, suggesting that the sprat gulped atmospheric air during its excursions to the surface. While the surface activity increased after the fjord became ice covered, the records of gas release decreased sharply. The under-ice fish then displayed a behavior interpreted as "searching for the surface" by repeatedly ascending toward the ice, apparently with limited success of filling the swim bladder. This interpretation was supported by lower acoustic target strength in ice-covered waters. The frequent surfacing behavior demonstrated in this study indicates that gulping of atmospheric air is an important element in the life of sprat. While at least part of the population endured overwintering in the ice-covered habitat, ice covering may constrain those physostome fishes that lack a gas-generating gland in ways that remain to be established. 2013 The Author(s).

  8. High resolution electron energy loss spectroscopy of clean and hydrogen covered Si(001) surfaces: first principles calculations.

    Science.gov (United States)

    Patterson, C H

    2012-09-07

    Surface phonons, conductivities, and loss functions are calculated for reconstructed (2×1), p(2×2) and c(4×2) clean Si(001) surfaces, and (2×1) H and D covered Si(001) surfaces. Surface conductivities perpendicular to the surface are significantly smaller than conductivities parallel to the surface. The surface loss function is compared to high resolution electron energy loss measurements. There is good agreement between calculated loss functions and experiment for H and D covered surfaces. However, agreement between experimental data from different groups and between theory and experiment is poor for clean Si(001) surfaces. Formalisms for calculating electron energy loss spectra are reviewed and the mechanism of electron energy losses to surface vibrations is discussed.

  9. Updating the 2001 National Land Cover Database Impervious Surface Products to 2006 using Landsat imagery change detection methods

    Science.gov (United States)

    Xian, George; Homer, Collin G.

    2010-01-01

    A prototype method was developed to update the U.S. Geological Survey (USGS) National Land Cover Database (NLCD) 2001 to a nominal date of 2006. NLCD 2001 is widely used as a baseline for national land cover and impervious cover conditions. To enable the updating of this database in an optimal manner, methods are designed to be accomplished by individual Landsat scene. Using conservative change thresholds based on land cover classes, areas of change and no-change were segregated from change vectors calculated from normalized Landsat scenes from 2001 and 2006. By sampling from NLCD 2001 impervious surface in unchanged areas, impervious surface predictions were estimated for changed areas within an urban extent defined by a companion land cover classification. Methods were developed and tested for national application across six study sites containing a variety of urban impervious surface. Results show the vast majority of impervious surface change associated with urban development was captured, with overall RMSE from 6.86 to 13.12% for these areas. Changes of urban development density were also evaluated by characterizing the categories of change by percentile for impervious surface. This prototype method provides a relatively low cost, flexible approach to generate updated impervious surface using NLCD 2001 as the baseline.

  10. Surface collisions of formic acid cations HCOOH+ and DCOOD+ with a hydrocarbon-covered stainless steel surface

    Science.gov (United States)

    Tepnual, Thawatchai; Feketeová, Linda; Grill, Verena; Scheier, Paul; Herman, Zdenek; Märk, Tilmann D.

    2005-07-01

    Interaction of the formic acid cation HCOOH+ with a stainless steel surface covered with hydrocarbons has been studied as a function of the collision energy from a few eV up to 40 eV. Mass spectra of the product ions showed ions produced by surface-induced dissociation of the projectile and formation of HCO2H2+ in interaction with the surface material. The fragmentation of the projectile led to product ions HCOO+ and CHO+. The product ion HCO2H2+ fragmented to give only CHO+, indicating that its structure was HC(OH)2+ as suggested earlier by others. The results were confirmed by studies using the deuterated formic acid cation DCOOD+.

  11. Modeling surface energy fluxes and thermal dynamics of a seasonally ice-covered hydroelectric reservoir.

    Science.gov (United States)

    Wang, Weifeng; Roulet, Nigel T; Strachan, Ian B; Tremblay, Alain

    2016-04-15

    The thermal dynamics of human created northern reservoirs (e.g., water temperatures and ice cover dynamics) influence carbon processing and air-water gas exchange. Here, we developed a process-based one-dimensional model (Snow, Ice, WAater, and Sediment: SIWAS) to simulate a full year's surface energy fluxes and thermal dynamics for a moderately large (>500km(2)) boreal hydroelectric reservoir in northern Quebec, Canada. There is a lack of climate and weather data for most of the Canadian boreal so we designed SIWAS with a minimum of inputs and with a daily time step. The modeled surface energy fluxes were consistent with six years of observations from eddy covariance measurements taken in the middle of the reservoir. The simulated water temperature profiles agreed well with observations from over 100 sites across the reservoir. The model successfully captured the observed annual trend of ice cover timing, although the model overestimated the length of ice cover period (15days). Sensitivity analysis revealed that air temperature significantly affects the ice cover duration, water and sediment temperatures, but that dissolved organic carbon concentrations have little effect on the heat fluxes, and water and sediment temperatures. We conclude that the SIWAS model is capable of simulating surface energy fluxes and thermal dynamics for boreal reservoirs in regions where high temporal resolution climate data are not available. SIWAS is suitable for integration into biogeochemical models for simulating a reservoir's carbon cycle. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Experimental studies of microwave interaction with a plasma-covered planar conducting surface

    International Nuclear Information System (INIS)

    Destler, W.W.; Rodgers, J.; DeGrange, J.E.; Segalov, Z.

    1990-01-01

    The authors present experimental studies of the reflection and absorption of microwave radiation from a plasma-covered planar conducting surface. In the experiments, microwave radiation from both highpower, short pulse (10 GHz, 100 MW, 30 ns) and low power (10 GHz, 10 mW, CW) sources is radiated at a 30 cm diameter conducting plate. A time-varying plasma is created on the surface of the conductor by 19 coaxial plasma guns embedded in the surface of the plate and discharged using a fast-rise capacitor bank. The plasma density distribution on the conducting surface is a function of time and the charging voltage on the capacitor bank. Incident and reflected microwave radiation has been measured for a wide variety of experimental conditions

  13. ANALYSIS OF THE INTRA-CITY VARIATION OF URBAN HEAT ISLAND AND ITS RELATION TO LAND SURFACE/COVER PARAMETERS

    Directory of Open Access Journals (Sweden)

    D. Gerçek

    2016-06-01

    Full Text Available Along with urbanization, sealing of vegetated land and evaporation surfaces by impermeable materials, lead to changes in urban climate. This phenomenon is observed as temperatures several degrees higher in densely urbanized areas compared to the rural land at the urban fringe particularly at nights, so-called Urban Heat Island. Urban Heat Island (UHI effect is related with urban form, pattern and building materials so far as it is associated with meteorological conditions, air pollution, excess heat from cooling. UHI effect has negative influences on human health, as well as other environmental problems such as higher energy demand, air pollution, and water shortage. Urban Heat Island (UHI effect has long been studied by observations of air temperature from thermometers. However, with the advent and proliferation of remote sensing technology, synoptic coverage and better representations of spatial variation of surface temperature became possible. This has opened new avenues for the observation capabilities and research of UHIs. In this study, "UHI effect and its relation to factors that cause it" is explored for İzmit city which has been subject to excess urbanization and industrialization during the past decades. Spatial distribution and variation of UHI effect in İzmit is analysed using Landsat 8 and ASTER day & night images of 2015 summer. Surface temperature data derived from thermal bands of the images were analysed for UHI effect. Higher temperatures were classified into 4 grades of UHIs and mapped both for day and night. Inadequate urban form, pattern, density, high buildings and paved surfaces at the expanse of soil ground and vegetation cover are the main factors that cause microclimates giving rise to spatial variations in temperatures across cities. These factors quantified as land surface/cover parameters for the study include vegetation index (NDVI, imperviousness (NDISI, albedo, solar insolation, Sky View Factor (SVF, building

  14. Analysis of the Intra-City Variation of Urban Heat Island and its Relation to Land Surface/cover Parameters

    Science.gov (United States)

    Gerçek, D.; Güven, İ. T.; Oktay, İ. Ç.

    2016-06-01

    Along with urbanization, sealing of vegetated land and evaporation surfaces by impermeable materials, lead to changes in urban climate. This phenomenon is observed as temperatures several degrees higher in densely urbanized areas compared to the rural land at the urban fringe particularly at nights, so-called Urban Heat Island. Urban Heat Island (UHI) effect is related with urban form, pattern and building materials so far as it is associated with meteorological conditions, air pollution, excess heat from cooling. UHI effect has negative influences on human health, as well as other environmental problems such as higher energy demand, air pollution, and water shortage. Urban Heat Island (UHI) effect has long been studied by observations of air temperature from thermometers. However, with the advent and proliferation of remote sensing technology, synoptic coverage and better representations of spatial variation of surface temperature became possible. This has opened new avenues for the observation capabilities and research of UHIs. In this study, "UHI effect and its relation to factors that cause it" is explored for İzmit city which has been subject to excess urbanization and industrialization during the past decades. Spatial distribution and variation of UHI effect in İzmit is analysed using Landsat 8 and ASTER day & night images of 2015 summer. Surface temperature data derived from thermal bands of the images were analysed for UHI effect. Higher temperatures were classified into 4 grades of UHIs and mapped both for day and night. Inadequate urban form, pattern, density, high buildings and paved surfaces at the expanse of soil ground and vegetation cover are the main factors that cause microclimates giving rise to spatial variations in temperatures across cities. These factors quantified as land surface/cover parameters for the study include vegetation index (NDVI), imperviousness (NDISI), albedo, solar insolation, Sky View Factor (SVF), building envelope

  15. Effect of rock fragment embedding on the aeolian deposition of dust on stone-covered surfaces

    NARCIS (Netherlands)

    Goossens, D.

    2005-01-01

    Many stone-covered surfaces on Earth are subject to aeolian deposition of atmospheric dust. This study investigates how the deposition of dust is affected when rock fragments become gradually more embedded in the ground or, inversely, become more concentrated on the surface. Experiments were

  16. A high resolution photoemission study of surface core-level shifts in clean and oxygen-covered Ir(2 1 0) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gladys, M.J.; Ermanoski, I.; Jackson, G.; Quinton, J.S.; Rowe, J.E.; Madey, T.E. E-mail: madey@physics.rutgers.edu

    2004-04-01

    High resolution soft X-ray photoemission electron spectroscopy (SXPS), using synchrotron radiation, is employed to investigate 4f core-level features of four differently-prepared Ir(2 1 0) surfaces: clean planar, oxygen-covered planar, oxygen-induced faceted, and clean faceted surfaces. Surface and bulk peak identifications are supported by measurements at different photon energies (thus probing different electron escape depths) and variable emission angles. Iridium 4f{sub 7/2} photoemission spectra are fitted with Doniach-Sunjic lineshapes. The surface components are identified with core levels positioned at lower binding energies than the bulk components, in contrast to previous reports of binding energy inversion on Ir(1 0 0) (1x1) and (5x1) surfaces. For clean planar Ir(2 1 0) three surface Ir 4f{sub 7/2} features are observed with core-level shifts of -765, -529, and -281 meV, with respect to the bulk; these are associated with the first, second and third layers of atoms, respectively, for atomically rough Ir(2 1 0). Adsorption of oxygen onto the planar Ir(2 1 0) surface is found to cause a suppression and shift of the surface features to higher binding energies. Annealing at T{>=}600 K in oxygen produces a faceted surface as verified by low energy electron diffraction (LEED). A comparison of planar and faceted oxygen-covered surfaces reveals minor differences in the normal emission SXPS spectra, while grazing emission spectra exhibit differences. The SXPS spectrum of the clean, faceted Ir(2 1 0) exhibits small differences in comparison to the clean planar case, with surface features having binding energy shifts of -710, -450, and -230 meV.

  17. A prototype for automation of land-cover products from Landsat Surface Reflectance Data Records

    Science.gov (United States)

    Rover, J.; Goldhaber, M. B.; Steinwand, D.; Nelson, K.; Coan, M.; Wylie, B. K.; Dahal, D.; Wika, S.; Quenzer, R.

    2014-12-01

    Landsat data records of surface reflectance provide a three-decade history of land surface processes. Due to the vast number of these archived records, development of innovative approaches for automated data mining and information retrieval were necessary. Recently, we created a prototype utilizing open source software libraries for automatically generating annual Anderson Level 1 land cover maps and information products from data acquired by the Landsat Mission for the years 1984 to 2013. The automated prototype was applied to two target areas in northwestern and east-central North Dakota, USA. The approach required the National Land Cover Database (NLCD) and two user-input target acquisition year-days. The Landsat archive was mined for scenes acquired within a 100-day window surrounding these target dates, and then cloud-free pixels where chosen closest to the specified target acquisition dates. The selected pixels were then composited before completing an unsupervised classification using the NLCD. Pixels unchanged in pairs of the NLCD were used for training decision tree models in an iterative process refined with model confidence measures. The decision tree models were applied to the Landsat composites to generate a yearly land cover map and related information products. Results for the target areas captured changes associated with the recent expansion of oil shale production and agriculture driven by economics and policy, such as the increase in biofuel production and reduction in Conservation Reserve Program. Changes in agriculture, grasslands, and surface water reflect the local hydrological conditions that occurred during the 29-year span. Future enhancements considered for this prototype include a web-based client, ancillary spatial datasets, trends and clustering algorithms, and the forecasting of future land cover.

  18. Sub-pixel estimation of tree cover and bare surface densities using regression tree analysis

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Zangrando Toneli

    2011-09-01

    Full Text Available Sub-pixel analysis is capable of generating continuous fields, which represent the spatial variability of certain thematic classes. The aim of this work was to develop numerical models to represent the variability of tree cover and bare surfaces within the study area. This research was conducted in the riparian buffer within a watershed of the São Francisco River in the North of Minas Gerais, Brazil. IKONOS and Landsat TM imagery were used with the GUIDE algorithm to construct the models. The results were two index images derived with regression trees for the entire study area, one representing tree cover and the other representing bare surface. The use of non-parametric and non-linear regression tree models presented satisfactory results to characterize wetland, deciduous and savanna patterns of forest formation.

  19. Research on Land Surface Thermal-Hydrologic Exchange in Southern China under Future Climate and Land Cover Scenarios

    Directory of Open Access Journals (Sweden)

    Jianwu Yan

    2013-01-01

    Full Text Available Climate change inevitably leads to changes in hydrothermal circulation. However, thermal-hydrologic exchanging caused by land cover change has also undergone ineligible changes. Therefore, studying the comprehensive effects of climate and land cover changes on land surface water and heat exchanges enables us to well understand the formation mechanism of regional climate and predict climate change with fewer uncertainties. This study investigated the land surface thermal-hydrologic exchange across southern China for the next 40 years using a land surface model (ecosystem-atmosphere simulation scheme (EASS. Our findings are summarized as follows. (i Spatiotemporal variation patterns of sensible heat flux (H and evapotranspiration (ET under the land cover scenarios (A2a or B2a and climate change scenario (A1B are unanimous. (ii Both H and ET take on a single peak pattern, and the peak occurs in June or July. (iii Based on the regional interannual variability analysis, H displays a downward trend (10% and ET presents an increasing trend (15%. (iv The annual average H and ET would, respectively, increase and decrease by about 10% when woodland converts to the cultivated land. Through this study, we recognize that land surface water and heat exchanges are affected greatly by the future climate change as well as land cover change.

  20. A call for surveys

    DEFF Research Database (Denmark)

    Bernstein, Philip A.; Jensen, Christian S.; Tan, Kian-Lee

    2012-01-01

    The database field is experiencing an increasing need for survey papers. We call on more researchers to set aside time for this important writing activity. The database field is growing in population, scope of topics covered, and the number of papers published. Each year, thousands of new papers ...

  1. 40 CFR 761.375 - Specific requirements for surfaces coated or covered with dust, dirt, grime, grease, or another...

    Science.gov (United States)

    2010-07-01

    ... coated or covered with dust, dirt, grime, grease, or another absorbent material. 761.375 Section 761.375... coated or covered with dust, dirt, grime, grease, or another absorbent material. (a) First wash. Cover..., absorbent pad until the surface appears dry. This cleaning should remove any residual dirt, dust, grime, or...

  2. Optimal use of land surface temperature data to detect changes in tropical forest cover

    Science.gov (United States)

    Van Leeuwen, T. T.; Frank, A. J.; Jin, Y.; Smyth, P.; Goulden, M.; van der Werf, G.; Randerson, J. T.

    2011-12-01

    Rapid and accurate assessment of global forest cover change is needed to focus conservation efforts and to better understand how deforestation is contributing to the build up of atmospheric CO2. Here we examined different ways to use remotely sensed land surface temperature (LST) to detect changes in tropical forest cover. In our analysis we used monthly 0.05×0.05 degree Terra MODerate Resolution Imaging Spectroradiometer (MODIS) observations of LST and PRODES (Program for the Estimation of Deforestation in the Brazilian Amazon) estimates of forest cover change. We also compared MODIS LST observations with an independent estimate of forest cover loss derived from MODIS and Landsat observations. Our study domain of approximately 10×10 degree included most of the Brazilian state of Mato Grosso. For optimal use of LST data to detect changes in tropical forest cover in our study area, we found that using data sampled during the end of the dry season (~1-2 months after minimum monthly precipitation) had the greatest predictive skill. During this part of the year, precipitation was low, surface humidity was at a minimum, and the difference between day and night LST was the largest. We used this information to develop a simple temporal sampling algorithm appropriate for use in pan-tropical deforestation classifiers. Combined with the normalized difference vegetation index (NDVI), a logistic regression model using day-night LST did moderately well at predicting forest cover change. Annual changes in day-night LST difference decreased during 2006-2009 relative to 2001-2005 in many regions within the Amazon, providing independent confirmation of lower deforestation levels during the latter part of this decade as reported by PRODES. The use of day-night LST differences may be particularly valuable for use with satellites that do not have spectral bands that allow for the estimation of NDVI or other vegetation indices.

  3. Surface core level shifts of clean and oxygen covered Ir(111)

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, M; Cassese, D; Cavallin, A; Comin, R; Orlando, F; Postregna, L [Universita degli Studi di Trieste, Via A Valerio 2, 34127, Trieste (Italy); Golfetto, E; Baraldi, A [Dipartimento di Fisica e CENMAT, Universita degli Studi di Trieste, Via A Valerio 2, 34127, Trieste (Italy); Lizzit, S [Sincrotrone Trieste S.C.p.A., S.S. 14 Km 163.5, 34012 Trieste (Italy)], E-mail: alessandro.baraldi@elettra.trieste.it

    2009-06-15

    We present the results of high resolution core level photoelectron spectroscopy employed to investigate the electronic structure of clean and oxygen covered Ir(111) surface. Ir 4f{sub 7/2} core level spectra are shown to be very sensitive to the local atomic environment. For the clean surface we detected two distinct components shifted by 550 meV, originated by surface and bulk atoms. The larger Gaussian width of the bulk component is explained as due to experimentally unresolved subsurface components. In order to determine the relevance of the phonon contribution we examined the thermal behaviour of the core level lineshape using the Hedin-Rosengren theory. From the phonon-induced spectral broadening we found the Debye temperature of bulk and surface atoms to be 298 and 181 K, respectively, which confirms the softening of the vibrational modes at the surface. Oxygen adsorption leads to the appearance of new surface core level components at -200 meV and +230 meV, which are interpreted as due to first-layer Ir atoms differently coordinated with oxygen. The coverage dependence of these components demonstrates that the oxygen saturation corresponds to 0.38 ML, in good agreement with recent density functional theory calculations.

  4. Forward-looking Assimilation of MODIS-derived Snow Covered Area into a Land Surface Model

    Science.gov (United States)

    Zaitchik, Benjamin F.; Rodell, Matthew

    2008-01-01

    Snow cover over land has a significant impact on the surface radiation budget, turbulent energy fluxes to the atmosphere, and local hydrological fluxes. For this reason, inaccuracies in the representation of snow covered area (SCA) within a land surface model (LSM) can lead to substantial errors in both offline and coupled simulations. Data assimilation algorithms have the potential to address this problem. However, the assimilation of SCA observations is complicated by an information deficit in the observation SCA indicates only the presence or absence of snow, and not snow volume and by the fact that assimilated SCA observations can introduce inconsistencies with atmospheric forcing data, leading to non-physical artifacts in the local water balance. In this paper we present a novel assimilation algorithm that introduces MODIS SCA observations to the Noah LSM in global, uncoupled simulations. The algorithm utilizes observations from up to 72 hours ahead of the model simulation in order to correct against emerging errors in the simulation of snow cover while preserving the local hydrologic balance. This is accomplished by using future snow observations to adjust air temperature and, when necessary, precipitation within the LSM. In global, offline integrations, this new assimilation algorithm provided improved simulation of SCA and snow water equivalent relative to open loop integrations and integrations that used an earlier SCA assimilation algorithm. These improvements, in turn, influenced the simulation of surface water and energy fluxes both during the snow season and, in some regions, on into the following spring.

  5. Surface erosion and hydrology of earth covers used in shallow land burial of low-level radioactive waste

    International Nuclear Information System (INIS)

    Bent, G.C.

    1988-01-01

    Shallow land burial is the current method of disposal of low-level radioactive waste in the United States. The most serious technical problems encountered in shallow land burial are water-related. Water is reported to come into contact with the waste by erosion of earth covers or through infiltration of precipitation through the earth covers. The objectives of this study were to: compare and evaluate the effects of crested wheatgrass and streambank wheatgrass on surface erosion of simulated earth covers at Idaho National Engineering Laboratory (INEL), characterize the surface hydrology, and estimate cumulative soil loss for average and extreme rainfall events and determine if the waste will become exposed during its burial life due to erosion. 30 refs., 26 figs., 21 tabs

  6. On numerically pluricanonical cyclic coverings

    International Nuclear Information System (INIS)

    Kulikov, V S; Kharlamov, V M

    2014-01-01

    We investigate some properties of cyclic coverings f:Y→X (where X is a complex surface of general type) branched along smooth curves B⊂X that are numerically equivalent to a multiple of the canonical class of X. Our main results concern coverings of surfaces of general type with p g =0 and Miyaoka-Yau surfaces. In particular, such coverings provide new examples of multi-component moduli spaces of surfaces with given Chern numbers and new examples of surfaces that are not deformation equivalent to their complex conjugates

  7. Surface covering of downed logs: drivers of a neglected process in dead wood ecology.

    Science.gov (United States)

    Dynesius, Mats; Gibb, Heloise; Hjältén, Joakim

    2010-10-07

    Many species use coarse woody debris (CWD) and are disadvantaged by the forestry-induced loss of this resource. A neglected process affecting CWD is the covering of the surfaces of downed logs caused by sinking into the ground (increasing soil contact, mostly covering the underside of the log), and dense overgrowth by ground vegetation. Such cover is likely to profoundly influence the quality and accessibility of CWD for wood-inhabiting organisms, but the factors affecting covering are largely unknown. In a five-year experiment we determined predictors of covering rate of fresh logs in boreal forests and clear-cuts. Logs with branches were little covered because they had low longitudinal ground contact. For branchless logs, longitudinal ground contact was most strongly related to estimated peat depth (positive relation). The strongest predictor for total cover of branchless logs was longitudinal ground contact. To evaluate the effect on cover of factors other than longitudinal ground contact, we separately analyzed data from only those log sections that were in contact with the ground. Four factors were prominent predictors of percentage cover of such log sections: estimated peat depth, canopy shade (both increasing cover), potential solar radiation calculated from slope and slope aspect, and diameter of the log (both reducing cover). Peat increased cover directly through its low resistance, which allowed logs to sink and soil contact to increase. High moisture and low temperatures in pole-ward facing slopes and under a canopy favor peat formation through lowered decomposition and enhanced growth of peat-forming mosses, which also proved to rapidly overgrow logs. We found that in some boreal forests, peat and fast-growing mosses can rapidly cover logs lying on the ground. When actively introducing CWD for conservation purposes, we recommend that such rapid covering is avoided, thereby most likely improving the CWD's longevity as habitat for many species.

  8. Influence of cloud fraction and snow cover to the variation of surface UV radiation at King Sejong station, Antarctica

    Science.gov (United States)

    Lee, Yun Gon; Koo, Ja-Ho; Kim, Jhoon

    2015-10-01

    This study investigated how cloud fraction and snow cover affect the variation of surface ultraviolet (UV) radiation by using surface Erythemal UV (EUV) and Near UV (NUV) observed at the King Sejong Station, Antarctica. First the Radiative Amplification Factor (RAF), the relative change of surface EUV according to the total-column ozone amount, is compared for different cloud fractions and solar zenith angles (SZAs). Generally, all cloudy conditions show that the increase of RAF as SZA becomes larger, showing the larger effects of vertical columnar ozone. For given SZA cases, the EUV transmission through mean cloud layer gradually decreases as cloud fraction increases, but sometimes the maximum of surface EUV appears under partly cloudy conditions. The high surface EUV transmittance under broken cloud conditions seems due to the re-radiation of scattered EUV by cloud particles. NUV transmission through mean cloud layer also decreases as cloud amount increases but the sensitivity to the cloud fraction is larger than EUV. Both EUV and NUV radiations at the surface are also enhanced by the snow cover, and their enhancement becomes higher as SZA increases implying the diurnal variation of surface albedo. This effect of snow cover seems large under the overcast sky because of the stronger interaction between snow surface and cloudy sky.

  9. Surface runoff and soil erosion by difference of surface cover characteristics using by an oscillating rainfall simulator

    Science.gov (United States)

    Kim, J. K.; Kim, M. S.; Yang, D. Y.

    2017-12-01

    Sediment transfer within hill slope can be changed by the hydrologic characteristics of surface material on hill slope. To better understand sediment transfer of the past and future related to climate changes, studies for the changes of soil erosion due to hydrological characteristics changes by surface materials on hill slope are needed. To do so, on-situ rainfall simulating test was conducted on three different surface conditions, i.e. well covered with litter layer condition (a), undisturbed bare condition (b), and disturbed bare condition (c) and these results from rainfall simulating test were compared with that estimated using the Limburg Soil Erosion Model (LISEM). The result from the rainfall simulating tests showed differences in the infiltration rate (a > b > c) and the highest soil erosion rate was occurred on c condition. The result from model also was similar to those from rainfall simulating tests, however, the difference from the value of soil erosion rate between two results was quite large on b and c conditions. These results implied that the difference of surface conditions could change the surface runoff and soil erosion and the result from the erosion model might significantly underestimate on bare surface conditions rather than that from rainfall simulating test.

  10. Land management and land-cover change have impacts of similar magnitude on surface temperature

    DEFF Research Database (Denmark)

    Luyssaert, Sebastiaan; Jammet, Mathilde; Stoy, Paul C.

    2014-01-01

    Anthropogenic changes to land cover (LCC) remain common, but continuing land scarcity promotes the widespread intensification of land management changes (LMC) to better satisfy societal demand for food, fibre, fuel and shelter1. The biophysical effects of LCC on surface climate are largely unders...

  11. Rainfall runoff and erosion in Napa Valley vineyards: effects of slope, cover and surface roughness

    Science.gov (United States)

    Battany, M. C.; Grismer, M. E.

    2000-05-01

    The effects of slope, cover and surface roughness on rainfall runoff, infiltration and erosion were determined at two sites on a hillside vineyard in Napa County, California, using a portable rainfall simulator. Rainfall simulation experiments were carried out at two sites, with five replications of three slope treatments (5%, 10% and 15%) in a randomized block design at each site (0%bsol;64 m2 plots). Prior to initiation of the rainfall simulations, detailed assessments, not considered in previous vineyard studies, of soil slope, cover and surface roughness were conducted. Significant correlations (at the 95% confidence level) between the physical characteristics of slope, cover and surface roughness, with total infiltration, runoff, sediment discharge and average sediment concentration were obtained. The extent of soil cracking, a physical characteristic not directly measured, also affected analysis of the rainfall-runoff-erosion process. Average cumulative runoff and cumulative sediment discharge from site A was 87% and 242% greater, respectively, than at site B. This difference was linked to the greater cover, extent of soil cracking and bulk density at site B than at site A. The extent of soil cover was the dominant factor limiting soil loss when soil cracking was not present. Field slopes within the range of 4-16%, although a statistically significant factor affecting soil losses, had only a minor impact on the amount of soil loss. The Horton infiltration equation fit field data better than the modified Philip's equation. Owing to the variability in the treatment parameters affecting the rainfall-runoff-erosion process, use of ANOVA methods were found to be inappropriate; multiple-factor regression analysis was more useful for identifying significant parameters. Overall, we obtained similar values for soil erosion parameters as those obtained from vineyard erosion studies in Europe. In addition, it appears that results from the small plot studies may be

  12. Impacts of land use and land cover on surface and air temperature in urban landscapes

    Science.gov (United States)

    Crum, S.; Jenerette, D.

    2015-12-01

    Accelerating urbanization affects regional climate as the result of changing land cover and land use (LCLU). Urban land cover composition may provide valuable insight into relationships among urbanization, air, and land-surface temperature (Ta and LST, respectively). Climate may alter these relationships, where hotter climates experience larger LULC effects. To address these hypotheses we examined links between Ta, LST, LCLU, and vegetation across an urban coastal to desert climate gradient in southern California, USA. Using surface temperature radiometers, continuously measuring LST on standardized asphalt, concrete, and turf grass surfaces across the climate gradient, we found a 7.2°C and 4.6°C temperature decrease from asphalt to vegetated cover in the coast and desert, respectively. There is 131% more temporal variation in asphalt than turf grass surfaces, but 37% less temporal variation in concrete than turf grass. For concrete and turf grass surfaces, temporal variation in temperature increased from coast to desert. Using ground-based thermal imagery, measuring LST for 24 h sequences over citrus orchard and industrial use locations, we found a 14.5°C temperature decrease from industrial to orchard land use types (38.4°C and 23.9°C, respectively). Additionally, industrial land use types have 209% more spatial variation than orchard (CV=0.20 and 0.09, respectively). Using a network of 300 Ta (iButton) sensors mounted in city street trees throughout the region and hyperspectral imagery data we found urban vegetation greenness, measured using the normalized difference vegetation index (NDVI), was negatively correlated to Ta at night across the climate gradient. Contrasting previous findings, the closest coupling between NDVI and Ta is at the coast from 0000 h to 0800 h (highest r2 = 0.6, P urbanized regions of southern California, USA decrease Ta and LST and spatial variation in LST, while built surfaces and land uses have the opposite effect. Furthermore

  13. Possibility of oil film detection on the ice cover of the sea surface

    International Nuclear Information System (INIS)

    Levin, I.M.; Radomyslskaya, T.M.; Osadchy, V.J.; Rybalka, N.N.; Klementieva, N.Y.; Zhou, J.; Li, Z.

    2009-01-01

    Ice cover in the Arctic regions makes the application of traditional remote methods of environmental monitoring difficult, and can also prevent the use of probes or other measurement tools. This paper presented a method of detecting oil pollution on ice-covered sea surfaces. The method was able to detect oil films on the lower ice-water boundary from above and below under both natural and artificial illumination. Pollution was detected when the sensor signal, the apparent contrast of oil-ice, and signal-noise ratio exceeded corresponding threshold values. A standard TV system at a low altitude was used to detect oil pollution on pure crystalline ice with a snow cover from 0.6 to 0.8 meters to several meters thick. At higher altitudes, the contrast in oil and water decreased due to the presence of atmospheric haze. Underwater pulsed-laser imaging systems were used to detect oil pollution when ice was covered by with soot, dust, aquatic plants, and phytoplankton pigments. It was concluded that both methods can be used to detect oil on the water-ice boundary. 10 refs., 1 tab., 5 figs

  14. Change In Minimum Temperature As A Response To Land Cover Change In South Florida

    Science.gov (United States)

    Kandel, H. P.; Melesse, A. M.

    2012-12-01

    Replacement of higher evapotranspirative surface materials such as water and vegetation cover by other materials such as buildings, roads, and pavements increases the Bowen's ratio from about 0.5-2.0 in rural to about ≈ 5.0 in urban areas resulting in higher surface and near surface atmospheric temperatures in the urban areas (Taha, 1997). This effect is intensified by low emissivity surfaces of the urban covers storing more heat energy during day time, but emitting less during night compared to the energy emitted by rural covers causing higher night time temperatures in urban centers, an effect called Urban Heat Island (UHI). South Florida has undergone tremendous land cover change from its pre-drainage vegetated and wetlands to post drainage agricultural and urban lands, especially after late 20th century. The objective of this study was to simultaneously analyze the land use/ land cover change and the rural/ urban minimum temperatures in south Florida for the period representing pre and post drainage states. The result shows urban sprawl increased from 8% at the beginning of the analysis period to about 14% at the end. Green vegetated areas, shrubs, and forests are found to be declined. The minimum temperature is found increased as maximum as 2°F in the urbanized stations, which remained constant or shows negligible increase in rural stations. The study dictates further micro level scrutiny in order to reach a conclusion on the development of UHI in south Florida. Key words: Bowen's ratio, emissivity, urban heat island

  15. Impacts of land use and land cover change on surface runoff, discharge and low flows: Evidence from East Africa

    Directory of Open Access Journals (Sweden)

    A.C. Guzha

    2018-02-01

    New hydrological insights: Forest cover loss is accompanied by increased stream discharges and surface runoff. No significant difference in stream discharge is observed between bamboo and pine plantation catchments, and between cultivated and tea plantation catchments. Trend analyses show that despite forest cover loss, 63% of the watersheds show non-significant changes in annual discharges while 31% show increasing trends. Half of the watersheds show non-significant trends in wet season flows and low flows while 35% reveal decreasing trends in low flows. Modeling studies estimate that forest cover loss increases annual discharges and surface runoff by 16 ± 5.5% and 45 ± 14%, respectively. Peak flows increased by a mean of 10 ± 2.8% while low flows decreased by a mean of 7 ± 5.3%. Increased forest cover decreases annual discharges and surface runoff by 13 ± 1.9% and 25 ± 5%, respectively. Weak correlations between forest cover and runoff (r = 0.42, p < 0.05, mean discharge (r = 0.63, p < 0.05 and peak discharge (r = 0.67, p < 0.05 indicate that forest cover alone is not an accurate predictor of hydrological fluxes in East African catchments. The variability in these results supports the need for long-term field monitoring to better understand catchment responses and to improve the calibration of currently used simulation models.

  16. Validation and application of help code used for design and review of cover of low and intermediate level radioactive waste disposal in near-surface facilities

    International Nuclear Information System (INIS)

    Fan Zhiwen; Gu Cunli; Zhang Jinsheng; Liu Xiuzhen

    1996-01-01

    The authors describes validation and application of HELP code used by the United States Environmental Protective Agency for design and review of cover of low and intermediate level radioactive waste disposal in near-surface facilities. The HELP code was validated using data of field aerated moisture movement test by China Institute for Radiation Protection. The results show that simulation of HELP code is reasonable. Effects of surface layer thickness and surface treatment on moisture distribution in a cover was simulated with HELP code in the conditions of south-west China. The simulation results demonstrated that surface plantation of a cover plays very important role in moisture distribution in the cover. Special attention should be paid in cover design. In humid area, radioactive waste disposal safety should take full consideration with functions of chemical barrier. It was recommended that engineering economy should be added in future cover research so as to achieve optimization of cover design

  17. External GSM phone calls now made simpler

    CERN Multimedia

    2007-01-01

    On 2 July, the IT/CS Telecom Service introduced a new service making external calls from CERN GSM phones easier. A specific prefix is no longer needed for calls outside CERN. External calls from CERN GSM phones are to be simplified. It is no longer necessary to use a special prefix to call an external number from the CERN GSM network.The Telecom Section of the IT/CS Group is introducing a new system that will make life easier for GSM users. It is no longer necessary to use a special prefix (333) to call an external number from the CERN GSM network. Simply dial the number directly like any other Swiss GSM customer. CERN currently has its own private GSM network with the Swiss mobile operator, Sunrise, covering the whole of Switzerland. This network was initially intended exclusively for calls between CERN numbers (replacing the old beeper system). A special system was later introduced for external calls, allowing them to pass thr...

  18. Effects of Topography and Surface Soil Cover on Erosion for Mining Reclamation: The Experimental Spoil Heap at El Machorro Mine (Central Spain)

    OpenAIRE

    Martín Moreno, Cristina; Martín Duque, J. F.; Nicolau, J. M.; Hernando, N.; Sanz, M. A.; Sánchez Castillo, L.

    2013-01-01

    Mining reclamation tries to reduce environmental impacts, including accelerated runoff, erosion and sediment load in the nearby fluvial networks and their ecosystems. This study compares the effects of topography and surface soil cover on erosion on man-made slopes coming from surface mining reclamation in Central Spain. Two topographic profiles, linear and concave, with two surface soil covers, subsoil and topsoil, were monitored for two hydrologic years. Sediment load, rill development and ...

  19. Evapotranspiration (ET) covers.

    Science.gov (United States)

    Rock, Steve; Myers, Bill; Fiedler, Linda

    2012-01-01

    Evapotranspiration (ET) cover systems are increasingly being used at municipal solid waste (MSW) landfills, hazardous waste landfills, at industrial monofills, and at mine sites. Conventional cover systems use materials with low hydraulic permeability (barrier layers) to minimize the downward migration of water from the surface to the waste (percolation), ET cover systems use water balance components to minimize percolation. These cover systems rely on soil to capture and store precipitation until it is either transpired through vegetation or evaporated from the soil surface. Compared to conventional membrane or compacted clay cover systems, ET cover systems are expected to cost less to construct. They are often aesthetic because they employ naturalized vegetation, require less maintenance once the vegetative system is established, including eliminating mowing, and may require fewer repairs than a barrier system. All cover systems should consider the goals of the cover in terms of protectiveness, including the pathways of risk from contained material, the lifecycle of the containment system. The containment system needs to be protective of direct contact of people and animals with the waste, prevent surface and groundwater water pollution, and minimize release of airborne contaminants. While most containment strategies have been based on the dry tomb strategy of keeping waste dry, there are some sites where adding or allowing moisture to help decompose organic waste is the current plan. ET covers may work well in places where complete exclusion of precipitation is not needed. The U.S. EPA Alternative Cover Assessment Program (ACAP), USDOE, the Nuclear Regulatory Commission, and others have researched ET cover design and efficacy, including the history of their use, general considerations in their design, performance, monitoring, cost, current status, limitations on their use, and project specific examples. An on-line database has been developed with information

  20. ANALYSING THE EFFECTS OF DIFFERENT LAND COVER TYPES ON LAND SURFACE TEMPERATURE USING SATELLITE DATA

    Directory of Open Access Journals (Sweden)

    A. Şekertekin

    2015-12-01

    Full Text Available Monitoring Land Surface Temperature (LST via remote sensing images is one of the most important contributions to climatology. LST is an important parameter governing the energy balance on the Earth and it also helps us to understand the behavior of urban heat islands. There are lots of algorithms to obtain LST by remote sensing techniques. The most commonly used algorithms are split-window algorithm, temperature/emissivity separation method, mono-window algorithm and single channel method. In this research, mono window algorithm was implemented to Landsat 5 TM image acquired on 28.08.2011. Besides, meteorological data such as humidity and temperature are used in the algorithm. Moreover, high resolution Geoeye-1 and Worldview-2 images acquired on 29.08.2011 and 12.07.2013 respectively were used to investigate the relationships between LST and land cover type. As a result of the analyses, area with vegetation cover has approximately 5 ºC lower temperatures than the city center and arid land., LST values change about 10 ºC in the city center because of different surface properties such as reinforced concrete construction, green zones and sandbank. The temperature around some places in thermal power plant region (ÇATES and ZETES Çatalağzı, is about 5 ºC higher than city center. Sandbank and agricultural areas have highest temperature due to the land cover structure.

  1. Analysing the Effects of Different Land Cover Types on Land Surface Temperature Using Satellite Data

    Science.gov (United States)

    Şekertekin, A.; Kutoglu, Ş. H.; Kaya, S.; Marangoz, A. M.

    2015-12-01

    Monitoring Land Surface Temperature (LST) via remote sensing images is one of the most important contributions to climatology. LST is an important parameter governing the energy balance on the Earth and it also helps us to understand the behavior of urban heat islands. There are lots of algorithms to obtain LST by remote sensing techniques. The most commonly used algorithms are split-window algorithm, temperature/emissivity separation method, mono-window algorithm and single channel method. In this research, mono window algorithm was implemented to Landsat 5 TM image acquired on 28.08.2011. Besides, meteorological data such as humidity and temperature are used in the algorithm. Moreover, high resolution Geoeye-1 and Worldview-2 images acquired on 29.08.2011 and 12.07.2013 respectively were used to investigate the relationships between LST and land cover type. As a result of the analyses, area with vegetation cover has approximately 5 ºC lower temperatures than the city center and arid land., LST values change about 10 ºC in the city center because of different surface properties such as reinforced concrete construction, green zones and sandbank. The temperature around some places in thermal power plant region (ÇATES and ZETES) Çatalağzı, is about 5 ºC higher than city center. Sandbank and agricultural areas have highest temperature due to the land cover structure.

  2. INTER-SEASONAL DYNAMICS OF VEGETATION COVER AND SURFACE TEMPERATURE DISTRIBUTION: A CASE STUDY OF ONDO STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    H. A. Ibitolu

    2016-06-01

    Full Text Available This study employs Landsat ETM+ satellite imagery to access the inter-seasonal variations of Surface Temperature and Vegetation cover in Ondo State in 2013. Also, air temperature data for year 2013 acquired from 3 synoptic meteorological stations across the state were analyzed. The Single-channel Algorithm was used to extract the surface temperature maps from the digital number embedded within the individual pixel. To understand the spatio-temporal distribution of LST and vegetation across the various landuse types, 200 sample points were randomly chosen, so that each land-use covers 40 points. Imagery for the raining season where unavailable because of the intense cloud cover. Result showed that the lowest air temperature of 20.9°C was in January, while the highest air temperature of 34°C occurred in January and March. There was a significant shift in the vegetation greenness over Ondo State, as average NDVI tend to increase from a weak positive value (0.189 to a moderate value (0.419. The LULC map revealed that vegetation cover occupied the largest area (65% followed by Built-up (26%, Swampy land (4%, Rock outcrop (3% and water bodies (2%. The surface temperature maps revealed that January has the lowest temperature of 10°C experienced in the coastal riverine areas of Ilaje and Igbokoda, while the highest temperature of 39°C observed in September is experienced on the rocky grounds. The study also showed the existence of pockets of Urban Heat Islands (UHI that are well scattered all over the state. This finding proves the capability and reliability of Satellite remote sensing for environmental studies.

  3. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    1999-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...... set. Particular studies are made of branched polynomial covering maps arising from Riemann surfaces and from knots in the 3-sphere....

  4. An energy balance model exploration of the impacts of interactions between surface albedo, cloud cover and water vapor on polar amplification

    Science.gov (United States)

    Södergren, A. Helena; McDonald, Adrian J.; Bodeker, Gregory E.

    2017-11-01

    We examine the effects of non-linear interactions between surface albedo, water vapor and cloud cover (referred to as climate variables) on amplified warming of the polar regions, using a new energy balance model. Our simulations show that the sum of the contributions to surface temperature changes due to any variable considered in isolation is smaller than the temperature changes from coupled feedback simulations. This non-linearity is strongest when all three climate variables are allowed to interact. Surface albedo appears to be the strongest driver of this non-linear behavior, followed by water vapor and clouds. This is because increases in longwave radiation absorbed by the surface, related to increases in water vapor and clouds, and increases in surface absorbed shortwave radiation caused by a decrease in surface albedo, amplify each other. Furthermore, our results corroborate previous findings that while increases in cloud cover and water vapor, along with the greenhouse effect itself, warm the polar regions, water vapor also significantly warms equatorial regions, which reduces polar amplification. Changes in surface albedo drive large changes in absorption of incoming shortwave radiation, thereby enhancing surface warming. Unlike high latitudes, surface albedo change at low latitudes are more constrained. Interactions between surface albedo, water vapor and clouds drive larger increases in temperatures in the polar regions compared to low latitudes. This is in spite of the fact that, due to a forcing, cloud cover increases at high latitudes and decreases in low latitudes, and that water vapor significantly enhances warming at low latitudes.

  5. A resistance representation of schemes for evaporation from bare and partly plant-covered surfaces for use in atmospheric models

    Energy Technology Data Exchange (ETDEWEB)

    Mihailovic, D.T.; Pielke, R.A.; Rajkovic, B.; Lee, T.J.; Jeftic, M. (Novi Sad Univ. (Yugoslavia) Colorado State Univ., Fort Collins (United States) Belgrade Univ. (Yugoslavia))

    1993-06-01

    In the parameterization of land surface processes, attention must be devoted to surface evaporation, one of the main processes in the air-land energy exchange. One of the most used approaches is the resistance representation which requires the calculation of aerodynamic resistances. These resistances are calculated using K theory for different morphologies of plant communities; then, the performance of the evaporation schemes within the alpha, beta, and their combination approaches that parameterize evaporation from bare and partly plant-covered soil surfaces are discussed. Additionally, a new alpha scheme is proposed based on an assumed power dependence alpha on volumetric soil moisture content and its saturated value. Finally, the performance of the considered and the proposed schemes is tested based on time integrations using real data. The first set was for 4 June 1982, and the second for 3 June 1981 at the experimental site in Rimski Sancevi, Yugoslavia, on chernozem soil, as representative for a bare, and partly plant-covered surface, respectively. 63 refs.

  6. Interfacial stability of soil covers on lined surface impoundments

    International Nuclear Information System (INIS)

    Mitchell, D.H.; Gates, T.E.

    1986-04-01

    The factors affecting the interfacial stability of soil covers on geomembranes were examined to determine the maximum stable slopes for soil cover/geomembrane systems. Several instances of instability of soil covers on geomembranes have occurred at tailings ponds, leaving exposed geomembranes with the potential for physical ddamage and possibly chemical and ultraviolet degradation. From an operator's viewpoint, it is desirable to maximize the slope of lined facilities in order to maximize the volume-to-area ratio; however, the likelihood for instability also increases with increasing slope. Frictional data obtained from direct shear tests are compared with stability data obtained using a nine-square-meter (m 2 ) engineering-scale test stand to verify that direct shear test data are valid in slope design calculations. Interfacial frictional data from direct shear tests using high-density polyethylene and a poorly graded sand cover agree within several degrees with the engineering-scale tests. Additional tests with other soils and geomembranes are planned. The instability of soil covers is not always an interfacial problem; soil erosion and limited drainage capacity are additional factors that must be considered in the design of covered slopes. 7 refs., 5 figs., 2 tabs

  7. An eddy covariance system to characterize the atmospheric surface layer and turbulent latent heat fluxes over a debris-covered Himalayan glacier.

    Science.gov (United States)

    Litt, Maxime; Steiner, Jakob F.; Stigter, Emmy E.; Immerzeel, Walter; Shea, Joseph Michael

    2017-04-01

    Over debris-covered glaciers, water content variations in the debris layer can drive significant changes in its thermal conductivity and significantly impact melt rates. Since sublimation and evaporation are favoured in high-altitude conditions, e.g., low atmospheric pressure and high wind speeds, they are expected to strongly influence the water balance of the debris-layer. Dedicated latent heat fluxes measurements at the debris surface are essential to characterize the debris heat conductivity in order to assess underlying ice melt. Furthermore, the contribution of the turbulent fluxes in the surface energy balance over debris covered glacier remains uncertain since they are generally evaluated through similarity methods which might not be valid in complex terrain. We present the first results of a 15-day eddy-covariance experiment installed at the end of the monsoon (September-October) on a 3-m tower above the debris-covered Lirung glacier in Nepal. The tower also included measurements of the 4 radiation components. The eddy covariance measurements allowed for the characterization of the turbulence in the atmospheric surface layer, as well as the direct measurements of evaporation, sublimation and turbulent sensible heat fluxes. The experiment helps us to evaluate the contribution of turbulent fluxes to the surface energy balance over this debris-covered glacier, through a precise characterization of the overlying turbulent atmospheric surface layer. It also helps to study the role of the debris-layer water content changes through evaporation and sublimation and its feedback on heat conduction in this layer. The large observed turbulent fluxes play a significant role in the energy balance at the debris surface and significantly influence debris moisture, conductivity and subsequently underlying ice melt.

  8. Immunoevasive protein (IEP)-containing surface layer covering polydnavirus particles is essential for viral infection.

    Science.gov (United States)

    Furihata, Shunsuke; Tanaka, Kohjiro; Ryuda, Masasuke; Ochiai, Masanori; Matsumoto, Hitoshi; Csikos, Gyorge; Hayakawa, Yoichi

    2014-01-01

    Polydnaviruses (PDVs) are unique symbiotic viruses associated with parasitoid wasps: PDV particles are injected into lepidopteran hosts along with the wasp eggs and express genes that interfere with aspects of host physiology such as immune defenses and development. Recent comparative genomic studies of PDVs have significantly improved our understanding of their origin as well as the genome organization. However, the structural features of functional PDV particles remain ambiguous. To clear up the structure of Cotesia kariyai PDV (CkPDV) particles, we focused on immunoevasive protein (IEP), which is a mediator of immunoevasion by the wasp from the encapsulation reaction of the host insect's hemocytes, because it has been demonstrated to be present on the surface of the virus particle. We discovered that IEP tends to polymerize and constitutes a previously unidentified thin surface layer covering CkPDV particles. This outermost surface layer looked fragile and was easily removed from CkPVD particles by mechanical stressors such as shaking, which prevented CkPDV from expressing the encoded genes in the host target tissues such as fat body or hemocytes. Furthermore, we detected IEP homologue gene expression in the wasp's venom reservoirs, implying IEP has another unknown biological function in the wasp or parasitized hosts. Taken together, the present results demonstrated that female C. kariyai wasps produce the fragile thin layer partly composed of IEP to cover the outer surfaces of CkPDV particles; otherwise, they cannot function as infectious agents in the wasp's host. The fact that IEP family proteins are expressed in both venom reservoirs and oviducts suggests an intimate relationship between both tissues in the development of the parasitism strategy of the wasp. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Calling under pressure: short-finned pilot whales make social calls during deep foraging dives.

    Science.gov (United States)

    Jensen, Frants H; Perez, Jacobo Marrero; Johnson, Mark; Soto, Natacha Aguilar; Madsen, Peter T

    2011-10-22

    Toothed whales rely on sound to echolocate prey and communicate with conspecifics, but little is known about how extreme pressure affects pneumatic sound production in deep-diving species with a limited air supply. The short-finned pilot whale (Globicephala macrorhynchus) is a highly social species among the deep-diving toothed whales, in which individuals socialize at the surface but leave their social group in pursuit of prey at depths of up to 1000 m. To investigate if these animals communicate acoustically at depth and test whether hydrostatic pressure affects communication signals, acoustic DTAGs logging sound, depth and orientation were attached to 12 pilot whales. Tagged whales produced tonal calls during deep foraging dives at depths of up to 800 m. Mean call output and duration decreased with depth despite the increased distance to conspecifics at the surface. This shows that the energy content of calls is lower at depths where lungs are collapsed and where the air volume available for sound generation is limited by ambient pressure. Frequency content was unaffected, providing a possible cue for group or species identification of diving whales. Social calls may be important to maintain social ties for foraging animals, but may be impacted adversely by vessel noise.

  10. Potential feedbacks between snow cover, soil moisture and surface energy fluxes in Southern Norway

    Science.gov (United States)

    Brox Nilsen, Irene; Tallaksen, Lena M.; Stordal, Frode

    2017-04-01

    At high latitudes, the snow season has become shorter during the past decades because snowmelt is highly sensitive to a warmer climate. Snowmelt influences the energy balance by changing the albedo and the partitioning between latent and sensible heat fluxes. It further influences the water balance by changing the runoff and soil moisture. In a previous study, we identified southern Norway as a region where significant temperature changes in summer could potentially be explained by land-atmosphere interactions. In this study we hypothesise that changes in snow cover would influence the summer surface fluxes in the succeeding weeks or months. The exceptionally warm summer of 2014 was chosen as a test bed. In Norway, evapotranspiration is not soil moisture limited, but energy limited, under normal conditions. During warm summers, however, such as in 2014, evapotranspiration can be restricted by the available soil moisture. Using the Weather Research and Forecasting (WRF) model we replace the initial ground conditions for 2014 with conditions representative of a snow-poor spring and a snow-rich spring. WRF was coupled to Noah-MP at 3 km horizontal resolution in the inner domain, and the simulations covered mid-May through September 2014. Boundary conditions used to force WRF were taken from the Era-Interim reanalysis. Snow, runoff, soil moisture and soil temperature observational data were provided by the Norwegian Water Resources and Energy Directorate for validation. The validation shows generally good agreement with observations. Preliminary results show that the reduced snowpack, hereafter "sim1" increased the air temperature by up to 5 K and the surface temperature by up to 10 K in areas affected by snow changes. The increased snowpack, hereafter "sim2", decreased the air and surface temperature by the same amount. These are weekly mean values for the first eight simulation weeks from mid May. Because of the higher net energy available ( 100 Wm-2) in sim 1, both

  11. Moisture content analysis of covered uranium mill tailings

    International Nuclear Information System (INIS)

    Mayer, D.W.; Beedlow, P.A.; Cadwell, L.L.

    1981-12-01

    The use of vegetation and rock covers to stabilize uranium mill tailings cover systems is being investigated by Pacific Northwest Laboratory. A modeling study of moisture movement through the tailings and cover layers was initiated to determine the effect of the stabilizing techniques. The cover system was simulated under climatic conditions occurring at Grand Junction, Colorado. The cover consisted of a layer of wet clay/gravel mix followed by a capillary barrier of washed rock and a surface layer of fill soil. Vegetation and rock were used to stabilize the surface layer. The simulation yielded moisture content and moisture storage values for the tailings and cover system along with information about moisture losses due to evaporation, transpiration, and drainage. The study demonstrates that different surface stabilization treatments lead to different degrees of moisture retention in the covered tailings pile. The evapotranspiration from vegetation can result in a relatively stable moisture content. Rock covers, however, may cause drainage to occur because they reduce evaporation and lead to a subsequent increase in moisture content. It is important to consider these effects when designing a surface stabilization treatment. Drainage may contribute to a groundwater pollution problem. A surface treatment that allows the cover system to dry out can increase the risk of atmospheric contamination through elevated radon emission rates

  12. Survival probability in small angle scattering of low energy alkali ions from alkali covered metal surfaces

    International Nuclear Information System (INIS)

    Neskovic, N.; Ciric, D.; Perovic, B.

    1982-01-01

    The survival probability in small angle scattering of low energy alkali ions from alkali covered metal surfaces is considered. The model is based on the momentum approximation. The projectiles are K + ions and the target is the (001)Ni+K surface. The incident energy is 100 eV and the incident angle 5 0 . The interaction potential of the projectile and the target consists of the Born-Mayer, the dipole and the image charge potentials. The transition probability function corresponds to the resonant electron transition to the 4s projectile energy level. (orig.)

  13. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    2002-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch ...... set. Particular studies are made of branched polynomial covering maps arising from Riemann surfaces and from knots in the 3-sphere. (C) 2001 Elsevier Science B.V. All rights reserved.......A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...

  14. Structure and optical properties of water covered Cu(110) surfaces

    International Nuclear Information System (INIS)

    Baghbanpourasl, A.

    2014-01-01

    In this thesis structural and optical properties of the water covered Cu(110) surface is studied using density functional theory within independent particle approximation. Several stable adsorption structures are studied such as water clusters (monomer, dimer, trimer, tetramer and pentamer), different hexagonal monolayers, partially dissociated water monolayers and three different types of chains among them a chain that consists of pentagon rings. For a copper surface in contact with water vapor, the energetically stable H 2 O/OH adsorbed structures are compared thermodynamically using adsorption free energy (change of free energy due to adsorption). Several phase diagrams with respect to temperature and pressure are calculated. It is found that among the large number of energetically stable structures (i.e. structures with positive adsorption energy ) only limited number of them are thermodynamically stable. These thermodynamically stable structures are the class of almost energetically degenerate hexagonal overlayers, one type of partially dissociated water structure that contains Bjerrum defect in the hydrogen bond network and pentagon chain. Since hydrogen atoms are light weight their vibrational effects can be considerable. Zero point vibration decreases the adsorption energy up to 0.1 eV and free energy of adsorbed molecules arising from vibrational degree of freedom can go up to -0.2 eV per adsorbed molecule at 500 Kelvin. However zero point energy and vibrational free energy of adsorbed molecules do not alter relative stability of the adsorbed structures. To account for the long range van der Waals interactions, a semi-empirical scheme is applied. Reflectance Anisotropy Spectroscopy (RAS) is a fast and non destructive optical method that can be used to prob the surface in different conditions such as vacuum and electro-chemical environment. Elasto-optic coeficients of bulk are calculated from first principles and the change of the RA spectrum of the bare Cu

  15. Surface Analysis of Railway Buffers Heads Covered with Bronze Using Laser Cladding

    Directory of Open Access Journals (Sweden)

    Sitarz M.

    2017-06-01

    Full Text Available Railway buffers during the operation are staying in almost permanent contact with each other, creating friction node in the point of contact of two railway buffer heads. In consequence of overcoming track curves, turnouts and unevenness of track, the railway buffer heads moves relative to each other causing friction, which results in its wear. When the wear is excessive, it might be a reason to withdrawn vehicle from service, it causes flattening of buffer head, and in consequence its abnormal cooperation. To avoid this phenomenon the buffer heads should be covered with graphitized grease, but this method has many disadvantages. Accordingly, it was found that it would be beneficial to cover the buffer head with bronze using laser cladding. In this article the metallographic and mechanical analysis of the newly created top layer of railway buffer head are presented. In article the results from tribological tests conducted on Amsler test bench are also presented. Based on test results described in article concluded that the layer of bronze coat on working surface of railway buffer head can be beneficial from operational point of view.

  16. Effect of land cover and green space on land surface temperature of a fast growing economic region in Malaysia

    Science.gov (United States)

    Sheikhi, A.; Kanniah, K. D.; Ho, C. H.

    2015-10-01

    Green space must be increased in the development of new cities as green space can moderate temperature in the cities. In this study we estimated the land surface temperature (LST) and established relationships between LST and land cover and various vegetation and urban surface indices in the Iskandar Malaysia (IM) region. IM is one of the emerging economic gateways of Malaysia, and is envisaged to transform into a metropolis by 2025. This change may cause increased temperature in IM and therefore we conducted a study by using Landsat 5 image covering the study region (2,217 km2) to estimate LST, classify different land covers and calculate spectral indices. Results show that urban surface had highest LST (24.49 °C) and the lowest temperature was recorded in, forest, rubber and water bodies ( 20.69 to 21.02°C). Oil palm plantations showed intermediate mean LST values with 21.65 °C. We further investigated the relationship between vegetation and build up densities with temperature. We extracted 1000 collocated pure pixels of Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Normalized Difference Built-up Index (NDBI), Urban Index (UI) and LST in the study area. Results show a strong and significant negative correlation with (R2= -0.74 and -0.79) respectively between NDVI, NDWI and LST . Meanwhile a strong positive correlation (R2=0.8 and 0.86) exists between NDBI, UI and LST. These results show the importance of increasing green cover in urban environment to combat any adverse effects of climate change.

  17. Controls on plant functional surface cover types along a precipitation gradient in the Negev Desert of Israel

    NARCIS (Netherlands)

    Buis, E.; Veldkamp, A.; Boeken, B.; Breemen, van N.

    2009-01-01

    We studied the controls on functional surface cover types in four catchments along a semi-arid to arid precipitation gradient in the northern Negev Desert of Israel. First, we selected four functional types, based on their unique water use and redistribution functionality: shrubs, Asphodelus

  18. The average covering tree value for directed graph games

    NARCIS (Netherlands)

    Khmelnitskaya, Anna Borisovna; Selcuk, Özer; Talman, Dolf

    We introduce a single-valued solution concept, the so-called average covering tree value, for the class of transferable utility games with limited communication structure represented by a directed graph. The solution is the average of the marginal contribution vectors corresponding to all covering

  19. Rye cover crop increases earthworm populations and reduces losses of broadcast, fall-applied, fertilizers in surface runoff

    Science.gov (United States)

    Corn (Zea mays L.) silage and soybean [Glycine max (L.) Merr.] rotations in the US Upper Midwest leave minimal amounts of surface residues, which can contribute to soil degradation and a reduction in water quality. Planting cover crops after harvest can reduce these concerns, but their effectiveness...

  20. Percent Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forests provide economic and ecological value. High percentages of forest cover (FORPCT) generally indicate healthier ecosystems and cleaner surface water. More...

  1. Extraction of pulsed ion beams from an anode covered with liquid material

    International Nuclear Information System (INIS)

    Kitamura, Akira; Yano, Syukuro

    1982-01-01

    In order to extend the life of anodes of pulsed ion diodes, a trial was made to extract ions from a plasma created by surface flashover on the oil-covered anode. The diode with this anode worked well as a so-called pinched electron beam diode. Production of proton beams of 10 kA with energies of about 400 keV was confirmed by measurements with biased ion collectors and those of prompt γ-rays from the reaction 19 F(p,γα) 16 O. Substantial reduction of damage and substantial extension of the life of the anode disc were realized. (author)

  2. Surface-enhanced Raman scattering from graphene covered gold nanocap arrays

    Science.gov (United States)

    Long, Kailin; Luo, Xiaoguang; Nan, Haiyan; Du, Deyang; Zhao, Weiwei; Ni, Zhenhua; Qiu, Teng

    2013-11-01

    This work reports an efficient method to fabricate large-area flexible substrates for surface enhanced Raman scattering (SERS) application. Our technique is based on a single-step direct imprint process via porous anodic alumina stamps. Periodic hexagonal arrangements of porous anodic alumina stamps are transferred to the polyethylene terephthalate substrates by mechanically printing process. Printed nanocaps will turn into "hot spots" for electromagnetic enhancement with a deposited gold film by high vacuum evaporation. The gaps between the nanocaps are controllable with a tight correspondence to the thickness of the deposited gold, which dramatically influence the enhancement factor. After covered with a single-layer graphene sheet, the gold nanocap substrate can be further optimized with an extra enhancement of Raman signals, and it is available for the trace detection of probe molecules. This convenient, simple, and low-cost method of making flexible SERS-active substrates potentially opens a way towards biochemical analysis and disease detection.

  3. Electronic structure and dynamics of metal and metal-covered surfaces

    International Nuclear Information System (INIS)

    Yang, Shu.

    1992-01-01

    The unoccupied electronic states of;Ni(111) and Al(111) have been studied using angle-resolved inverse-photoemission (IPE) spectroscopy. We have characterized the n = 1 image potential state on Ni(111) measuring an effective mass of m * /m = 1, consistent with recent two-photon photoemission results as well as theoretical calculations using a phase-analysis model, but differing considerably from the earlier angle-resolved IPE measurements. The bulk related features on Ni(111) observed in our experiment agree very well with an empirical Ni band structure calculation. On Al(111), we have conducted an extensive study of the image potential resonance using both angle-resolved IPE spectroscopy and tunneling spectroscopy with the scanning tunneling microscope. We have used Al as a testing case for both nearly-free-electron model and first-principles calculations were needed to obtain a semi-quantitative account of the bulk features of Al, a simple metal. Improved quantitative agreement occurred when excitation effects were considered. In addition, several surface resonance features have been identified and characterized on Al(111). We have also conducted a geometric structural investigation of a metal overlayer system, Ni/Cu(111), using high-resolution electron energy loss spectroscopy with CO as a probe molecule. The results indicate island formation and two-dimensional mixing at the initial stage of bimetallic interface formation. A new adsorption site with CO bonded to both Ni and Cu has been discovered on the Ni-Cu intermixed surface. IPE results for the Cu-covered Ni(111) surface show an enhanced angular range for the Cu image state. Finally, the unique ability of Auger-photoelectron coincidence spectroscopy to probing local valence electronic structure has been tested in a case study of TaC(111). A novel Auger decay channel has also been observed

  4. Calling under pressure: Short-finned pilot whales make social calls during deep foraging dives

    DEFF Research Database (Denmark)

    Jensen, Frants Havmand; Marrero Perez, Jacobo; Johnson, Mark

    2011-01-01

    Toothed whales rely on sound to echolocate prey and communicate with conspecifics, but little is known about how extreme pressure affects pneumatic sound production in deep-diving species with a limited air supply. The short-finned pilot whale (Globicephala macrorhynchus) is a highly social species...... among the deep-diving toothed whales, in which individuals socialize at the surface but leave their social group in pursuit of prey at depths of up to 1000 m. To investigate if these animals communicate acoustically at depth and test whether hydrostatic pressure affects communication signals, acoustic...... DTAGs logging sound, depth and orientation were attached to 12 pilot whales. Tagged whales produced tonal calls during deep foraging dives at depths of up to 800 m. Mean call output and duration decreased with depth despite the increased distance to conspecifics at the surface. This shows...

  5. Exact Cover Problem in Milton Babbitt's All-partition Array

    DEFF Research Database (Denmark)

    Bemman, Brian; Meredith, David

    2015-01-01

    One aspect of analyzing Milton Babbitt’s (1916–2011) all- partition arrays requires finding a sequence of distinct, non-overlapping aggregate regions that completely and exactly covers an irregular matrix of pitch class integers. This is an example of the so-called exact cover problem. Given a set...

  6. Percent Wetland Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be...

  7. Influence of cover defects on the attenuation of radon with earthen covers

    International Nuclear Information System (INIS)

    Kalkwarf, D.R.; Mayer, D.W.

    1983-11-01

    Experimental and theoretical evaluations of radon flux through laboratory-scale defective soil columns are presented together with a survey of literature on the formation and prevention of defects in soil covers. This report focuses on air-filled, centimeter-scale defects that are most probable in earthen covers for attenuating radon emission from uranium-mill tailings. Examples include shirnkage and erosion cracks, erosion piping, animal burrows and air channels formed by the biodegradation of vegetation roots. Calculations based on mathematical models indicate that collections of defects which could increase the radon flux from an earthen cover by a factor of two would be easily detected by visual inspection. However, these models ignore air-turbulence in the defect and drying of the soil around the defect. Laboratory measurements showed that turbulent diffusion of radon occurred through defects as narrow as 0.3 cm when subjected to a transverse air velocity of 1 to 6 miles per hour at the surface. Both turbulence and more-rapid drying of soil can accelerate radon flux to the cover surface. Consequently, recommended methods to inhibit defect formation should be applied. 29 references, 3 figures, 5 tables

  8. What is the role of historical anthropogenically-induced land-cover change on the surface climate of West Africa? Results from the LUCID intercomparison project

    Science.gov (United States)

    Souleymane, S.

    2015-12-01

    West Africa has been highlighted as a hot spot of land surface-atmosphere interactions. This study analyses the outputs of the project Land-Use and Climate, IDentification of Robust Impacts (LUCID) over West Africa. LUCID used seven atmosphere-land models with a common experimental design to explore the impacts of Land Use induced Land Cover Change (LULCC) that are robust and consistent across the climate models. Focusing the analysis on Sahel and Guinea, this study shows that, even though the seven climate models use the same atmospheric and land cover forcing, there are significant differences of West African Monsoon variability across the climate models. The magnitude of that variability differs significantly from model to model resulting two major "features": (1) atmosphere dynamics models; (2) how the land-surface functioning is parameterized in the Land surface Model, in particular regarding the evapotranspiration partitioning within the different land-cover types, as well as the role of leaf area index (LAI) in the flux calculations and how strongly the surface is coupled to the atmosphere. The major role that the models'sensitivity to land-cover perturbations plays in the resulting climate impacts of LULCC has been analysed in this study. The climate models show, however, significant differences in the magnitude and the seasonal partitioning of the temperature change. The LULCC induced cooling is directed by decreases in net shortwave radiation that reduced the available energy (QA) (related to changes in land-cover properties other than albedo, such as LAI and surface roughness), which decreases during most part of the year. The biophysical impacts of LULCC were compared to the impact of elevated greenhouse gases resulting changes in sea surface temperatures and sea ice extent (CO2SST). The results show that the surface cooling (related a decrease in QA) induced by the biophysical effects of LULCC are insignificant compared to surface warming (related an

  9. Trends in Upper-Level Cloud Cover and Surface Divergence Over the Tropical Indo-Pacific Ocean Between 1952 And 1997

    Science.gov (United States)

    Norris, Joel R.

    2005-01-01

    This study investigated the spatial pattern of linear trends in surface-observed upper-level (combined mid-level and High-level) cloud cover, precipitation, and surface divergence over the tropical Indo-Pacific Ocean during 1952-1957. Cloud values were obtained from the Extended Edited Cloud Report Archive (EECRA), precipitation values were obtained from the Hulme/Climate Research Unit Data Set, and surface divergence was alternatively calculated from wind reported Comprehensive Ocean-Atmosphere Data Set and from Smith and Reynolds Extended Reconstructed sea level pressure data.

  10. LEED crystallography studies of the structure of clean and adsorbate-covered Ir, Pt and Rh crystal surfaces

    International Nuclear Information System (INIS)

    Koestner, R.J.

    1982-08-01

    There have only been a few Low Energy Electron Diffraction (LEED) intensity analyses carried out to determine the structure of molecules adsorbed on metal surfaces; most surface crystallography studies concentrated on the structure of clean unreconstructed or atomic adsorbate-covered transition metal faces. The few molecular adsorption systems already investigated by dynamical LEED are CO on Ni(100), Cu(100) and Pd(100) as well as C 2 H 2 and C 2 H 4 adsorbed on Pt(111). The emphasis of this thesis research has been to extend the applicability of LEED crystallography to the more complicated unit cells found in molecular overlayers on transition metals or in there constructed surfaces of clean transition metals

  11. Adsorption, desorption, and film formation of quinacridone and its thermal cracking product indigo on clean and carbon-covered silicon dioxide surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Scherwitzl, Boris; Lassnig, Roman; Truger, Magdalena; Resel, Roland; Leising, Günther; Winkler, Adolf, E-mail: a.winkler@tugraz.at [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz (Austria)

    2016-09-07

    The evaporation of quinacridone from a stainless steel Knudsen cell leads to the partial decomposition of this molecule in the cell, due to its comparably high sublimation temperature. At least one additional type of molecules, namely indigo, could be detected in the effusion flux. Thermal desorption spectroscopy and atomic force microscopy have been used to study the co-deposition of these molecules on sputter-cleaned and carbon-covered silicon dioxide surfaces. Desorption of indigo appears at temperatures of about 400 K, while quinacridone desorbs at around 510 K. For quinacridone, a desorption energy of 2.1 eV and a frequency factor for desorption of 1 × 10{sup 19} s{sup −1} were calculated, which in this magnitude is typical for large organic molecules. A fraction of the adsorbed quinacridone molecules (∼5%) decomposes during heating, nearly independent of the adsorbed amount, resulting in a surface composed of small carbon islands. The sticking coefficients of indigo and quinacridone were found to be close to unity on a carbon covered SiO{sub 2} surface but significantly smaller on a sputter-cleaned substrate. The reason for the latter can be attributed to insufficient energy dissipation for unfavorably oriented impinging molecules. However, due to adsorption via a hot-precursor state, the sticking probability is increased on the surface covered with carbon islands, which act as accommodation centers.

  12. ON f-EDGE COVER-COLOURING OF SIMPLE GRAPHS

    Institute of Scientific and Technical Information of China (English)

    Song Huimin; Liu Guizhen

    2005-01-01

    An f-edge cover-colouring of a graph G = (V, E) is an assignment of colours to the edges of G such that every colour appears at each vertex υ∈ V at least f(υ) times.The maximum number of colours needed to f-edge cover colour G is called the f-edge cover chromatic index of G, denoted by χfc(G). This paper gives that min[d(ν)-1/f(ν)] ≤χfc(G) ≤min[d(υ)/f(υ)].

  13. Ground cover and tree growth on calcareous minesoils: Greater influence of soil surface than nitrogen rate or seed mix

    International Nuclear Information System (INIS)

    Kost, D.A.; Vimmerstedt, J.P.

    1994-01-01

    Growth of ground cover and trees was evaluated for five growing seasons on calcareous coal minesoil surfaces (standard graded topsoil, graded and ripped topsoil, graded gray cast overburden) in southeastern Ohio. Soil surface plots were seeded in September 1987 with either a standard herbaceous seed mix [orchardgrass (Dactylis glomerata L.), timothy (Phleum pratense L.), perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), Ranger alfalfa (Medicago sativa L.), Mammoth red clover (Trifolium pratense L.), Empire birdsfoot trefoil (Lotus corniculatus L.), and wheat (Triticum aestivum L.)], or a modified mix using no alfalfa and half the rate of orchardgrass. Nitrogen (45, 90, or 135 kg ha/N) was applied as ammonium nitrate in September 1987 and April 1989. White ash (Fraxinus americana L.), silver maple (Acer saccharinum L.), northern red oak (Quercus rubra L.), and eastern white pine (Pinus strobus L.) were planted in spring 1989 into 0.8 m-wide strips sprayed with glyphosate herbicide at 2.24 kg/ha in October 1988. Total cover and total biomass were highest in July 1989, following the last application of nitrogen fertilizer in April 1989. Total cover ranged from 44% to 56%, and total biomass ranged from 102 to 162 g/0.5 m 2 from 1990 to 1993. Total cover and total biomass were lower at the lowest nitrogen rate in 1989 only. Type of herbaceous seed mix did not affect growth of ground cover or trees. Overall tree survival was 82.0% the first year but declined to 40.6% after 5 yr. Survival varied significantly among all tree species (3.5% for pine, 22.2% for oak, 38.5% for maple, 98.1% for ash)

  14. LEED crystallography studies of the structure of clean and adsorbate-covered Ir, Pt and Rh crystal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Koestner, R.J.

    1982-08-01

    There have only been a few Low Energy Electron Diffraction (LEED) intensity analyses carried out to determine the structure of molecules adsorbed on metal surfaces; most surface crystallography studies concentrated on the structure of clean unreconstructed or atomic adsorbate-covered transition metal faces. The few molecular adsorption systems already investigated by dynamical LEED are CO on Ni(100), Cu(100) and Pd(100) as well as C/sub 2/H/sub 2/ and C/sub 2/H/sub 4/ adsorbed on Pt(111). The emphasis of this thesis research has been to extend the applicability of LEED crystallography to the more complicated unit cells found in molecular overlayers on transition metals or in there constructed surfaces of clean transition metals.

  15. An Automated Algorithm for Producing Land Cover Information from Landsat Surface Reflectance Data Acquired Between 1984 and Present

    Science.gov (United States)

    Rover, J.; Goldhaber, M. B.; Holen, C.; Dittmeier, R.; Wika, S.; Steinwand, D.; Dahal, D.; Tolk, B.; Quenzer, R.; Nelson, K.; Wylie, B. K.; Coan, M.

    2015-12-01

    Multi-year land cover mapping from remotely sensed data poses challenges. Producing land cover products at spatial and temporal scales required for assessing longer-term trends in land cover change are typically a resource-limited process. A recently developed approach utilizes open source software libraries to automatically generate datasets, decision tree classifications, and data products while requiring minimal user interaction. Users are only required to supply coordinates for an area of interest, land cover from an existing source such as National Land Cover Database and percent slope from a digital terrain model for the same area of interest, two target acquisition year-day windows, and the years of interest between 1984 and present. The algorithm queries the Landsat archive for Landsat data intersecting the area and dates of interest. Cloud-free pixels meeting the user's criteria are mosaicked to create composite images for training the classifiers and applying the classifiers. Stratification of training data is determined by the user and redefined during an iterative process of reviewing classifiers and resulting predictions. The algorithm outputs include yearly land cover raster format data, graphics, and supporting databases for further analysis. Additional analytical tools are also incorporated into the automated land cover system and enable statistical analysis after data are generated. Applications tested include the impact of land cover change and water permanence. For example, land cover conversions in areas where shrubland and grassland were replaced by shale oil pads during hydrofracking of the Bakken Formation were quantified. Analytical analysis of spatial and temporal changes in surface water included identifying wetlands in the Prairie Pothole Region of North Dakota with potential connectivity to ground water, indicating subsurface permeability and geochemistry.

  16. The National Land Cover Database

    Science.gov (United States)

    Homer, Collin G.; Fry, Joyce A.; Barnes, Christopher A.

    2012-01-01

    The National Land Cover Database (NLCD) serves as the definitive Landsat-based, 30-meter resolution, land cover database for the Nation. NLCD provides spatial reference and descriptive data for characteristics of the land surface such as thematic class (for example, urban, agriculture, and forest), percent impervious surface, and percent tree canopy cover. NLCD supports a wide variety of Federal, State, local, and nongovernmental applications that seek to assess ecosystem status and health, understand the spatial patterns of biodiversity, predict effects of climate change, and develop land management policy. NLCD products are created by the Multi-Resolution Land Characteristics (MRLC) Consortium, a partnership of Federal agencies led by the U.S. Geological Survey. All NLCD data products are available for download at no charge to the public from the MRLC Web site: http://www.mrlc.gov.

  17. Percent Forest Cover (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forests provide economic and ecological value. High percentages of forest cover (FORPCTFuture) generally indicate healthier ecosystems and cleaner surface water....

  18. The effects of additional black carbon on Arctic sea ice surface albedo: variation with sea ice type and snow cover

    OpenAIRE

    A. A. Marks; M. D. King

    2013-01-01

    Black carbon in sea ice will decrease sea ice surface albedo through increased absorption of incident solar radiation, exacerbating sea ice melting. Previous literature has reported different albedo responses to additions of black carbon in sea ice and has not considered how a snow cover may mitigate the effect of black carbon in sea ice. Sea ice is predominately snow covered. Visible light absorption and light scattering coefficients are calculated for a typical first year and multi-y...

  19. Call Forecasting for Inbound Call Center

    Directory of Open Access Journals (Sweden)

    Peter Vinje

    2009-01-01

    Full Text Available In a scenario of inbound call center customer service, the ability to forecast calls is a key element and advantage. By forecasting the correct number of calls a company can predict staffing needs, meet service level requirements, improve customer satisfaction, and benefit from many other optimizations. This project will show how elementary statistics can be used to predict calls for a specific company, forecast the rate at which calls are increasing/decreasing, and determine if the calls may stop at some point.

  20. GLCF: Landsat GeoCover

    Science.gov (United States)

    satellite imagery provided in a standardized, orthorectified format, covering the entire land surface of the * Orthorectification * Distribution Status * Hard Media Orders * Letters Delivered Quick Links * Create True Color

  1. Land-cover change detection

    Science.gov (United States)

    Chen, Xuexia; Giri, Chandra; Vogelmann, James

    2012-01-01

    Land cover is the biophysical material on the surface of the earth. Land-cover types include grass, shrubs, trees, barren, water, and man-made features. Land cover changes continuously.  The rate of change can be either dramatic and abrupt, such as the changes caused by logging, hurricanes and fire, or subtle and gradual, such as regeneration of forests and damage caused by insects (Verbesselt et al., 2001).  Previous studies have shown that land cover has changed dramatically during the past sevearal centuries and that these changes have severely affected our ecosystems (Foody, 2010; Lambin et al., 2001). Lambin and Strahlers (1994b) summarized five types of cause for land-cover changes: (1) long-term natural changes in climate conditions, (2) geomorphological and ecological processes, (3) human-induced alterations of vegetation cover and landscapes, (4) interannual climate variability, and (5) human-induced greenhouse effect.  Tools and techniques are needed to detect, describe, and predict these changes to facilitate sustainable management of natural resources.

  2. Variations of Near Surface Energy Balance Caused by Land Cover Changes in the Semiarid Grassland Area of China

    Directory of Open Access Journals (Sweden)

    Qun’ou Jiang

    2014-01-01

    Full Text Available This study applies the Dynamics of Land System (DLS model to simulating the land cover under the designed scenarios and then analyzes the effects of land cover conversion on energy flux in the semiarid grassland area of China with the Weather Research and Forecasting (WRF model. The results indicate that the grassland will show a steadily upgrowing trend under the coordinated environmental sustainability (CES scenario. Compared to the CES scenario, the rate of increase in grassland cover is lower, while the rate of increase in urban land cover will be higher under the rapid economic growth (REG scenario. Although the conversion from cropland to grassland will reduce the energy flux, the expansion of urban area and decreasing of forestry area will bring about more energy flux. As a whole, the energy flux of near surface will obviously not change under the CES scenario, and the climate therefore will not be possible to be influenced greatly by land cover change. The energy flux under the REG scenario is higher than that under the CES scenario. Those research conclusions can offer valuable information for the land use planning and climate change adaptation in the semiarid grassland area of China.

  3. Impact of land cover and population density on land surface temperature: case study in Wuhan, China

    Science.gov (United States)

    Li, Lin; Tan, Yongbin; Ying, Shen; Yu, Zhonghai; Li, Zhen; Lan, Honghao

    2014-01-01

    With the rapid development of urbanization, the standard of living has improved, but changes to the city thermal environment have become more serious. Population urbanization is a driving force of residential expansion, which predominantly influences the land surface temperature (LST). We obtained the land covers and LST maps of Wuhan from Landsat-5 images in 2000, 2002, 2005, and 2009, and discussed the distribution of land use/cover change and LST variation, and we analyzed the correlation between population distribution and LST values in residential regions. The results indicated massive variation of land cover types, which was shown as a reduction in cultivatable land and the expansion of building regions. High-LST regions concentrated on the residential and industrial areas with low vegetation coverage. In the residential region, the population density (PD) had effects on the LST values. Although the area or variation of residential regions was close, lower PD was associated with lower mean LST or LST variation. Thus, decreasing the high-LST regions concentration by reducing the PD may alleviate the urban heat island effect on the residential area. Taken together, these results can provide supports for urban planning projects and studies on city ecological environments.

  4. Percent of Impervious Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — High amounts of impervious cover (parking lots, rooftops, roads, etc.) can increase water runoff, which may directly enter surface water. Runoff from roads often...

  5. Absorption of Nickel, Chromium, and Iron by the Root Surface of Primary Molars Covered with Stainless Steel Crowns

    Directory of Open Access Journals (Sweden)

    David Keinan

    2010-01-01

    Full Text Available Objective. The purpose of this study was to analyze the absorption of metal ions released from stainless steel crowns by root surface of primary molars. Study Design. Laboratory research: The study included 34 primary molars, exfoliated or extracted during routine dental treatment. 17 molars were covered with stainless-steel crowns for more than two years and compared to 17 intact primary molars. Chemical content of the mesial or distal root surface, 1 mm apically to the crown or the cemento-enamel junction (CEJ, was analyzed. An energy dispersive X-ray spectrometer (EDS was used for chemical analysis. Results. Higher amounts of nickel, chromium, and iron (5-6 times were found in the cementum of molars covered with stainless-steel crowns compared to intact molars. The differences between groups were highly significant (<.001. Significance. Stainless-steel crowns release nickel, chromium, and iron in oral environment, and the ions are absorbed by the primary molars roots. The additional burden of allergenic metals should be reduced if possible.

  6. GEOEPIDERM – AN ECOLOGICAL CONCEPT THAT INTEGRATES SOIL COVER WITH ASSOCIATED LAND SURFACE COMPONENTS

    Directory of Open Access Journals (Sweden)

    I. Munteanu

    2008-10-01

    Full Text Available Based on the new concept of the “Epiderm of the Earth” introduced by the 2006 edition of the WRB-SR, the idea of “geoepiderm” has been developed. Besides its holistic meaning, by including both soil and non-soil materials found in the first 2 meters of the land surface, the term “geoepiderm” has a strong ecological sense, by suggesting similarity with the skin of the living organisms, as such, this concept is fully concordant with that of “Gaia” (Living Earth developed by James Lovelock. According to the main pedo-ecological characteristics of the soil and not soil coverings from the earth surface, ten kinds (classes of ‘geoepiderms” have been identified:1 – Protoderma (Entiderma– the primitive (emerging geoepiderm (mainly non-soil materials; five main subtypes: a Regoderma, b Leptoderma, c Areniderma, d Fluviderma and e Gleyoderma, were identified;2 – Cryoderma (Geliderma – geoepiderm of cold, mainly artic and subartic, regions with mean annual soil temperature <00C (often with perennial frozen subsoil - permafrost:3 – Arididerma – geoepiderm of arid regions and salt affected lands with limited or scarce available moisture; two subtypes: a Desertiderma, b Saliderma4 – Inceptiderma (or Juvenilederma – with 2 subtypes: a Cambiderma – a young (incipiently developed geoepiderm and b Andiderma, geoepiderm developed in volcanic materials;5 – Euderma – nutrient rich geoepiderm with two main subtypes: a Cherniderma (or Molliderma and b Luviderma (or Alfiderma;6 – Oligoderma – geoepiderm with low macro-nutrient and weatherable minerals content with 2 subtypes: a Podziderma (or Spodiderma and b Acriderma (or Ultiderma;7 – Ferriderma (Oxiderma or Senilederma – geoepiderm strongly weathered and with iron and aluminium hydroxides enrichment and low weatherable minerals reserve;8 – Vertiderma (Contractilederma – Contractile geoepiderm, developed from swelling clays;9 – Histoderma (Organiderma

  7. Revegetation/rock cover for stabilization of inactive uranium mill tailings disposal sites

    International Nuclear Information System (INIS)

    Beedlow, P.A.; McShane, M.C.; Cadwell, L.L.

    1982-07-01

    Pacific Northwest Laboratory is developing design and performance guidelines for surface stabilization of inactive uranium mill tailings. In this work, vegetation and rock covers are being evaluated for maintaining long-term integrity of impoundment systems. Methods are being developed to estimate erosion rates associated with rock and/or vegetation covers, and to determine the effects of surface treatments on soil moisture. Interactions between surface treatments and barriers (radon and biological) are being studied as well. The product will be a set of guidelines to aid in designing surface covers. This report presents the status of this program and a discussion of considerations pertinent to the application of surface covers to tailings. Test plots located in Grand Junction, Colorado and Waterflow, New Mexico are being used to study: (1) the interactions between vegetation and radon and biological barriers, (2) the effects of surface covers on soil moisture, and (3) the effects of rock covers on vegetation

  8. Exact Cover Problem in Milton Babbitt's All-partition Array

    OpenAIRE

    Bemman, Brian; Meredith, David

    2015-01-01

    One aspect of analyzing Milton Babbitt’s (1916–2011) all- partition arrays requires finding a sequence of distinct, non-overlapping aggregate regions that completely and exactly covers an irregular matrix of pitch class integers. This is an example of the so-called exact cover problem. Given a set, A, and a collection of distinct subsets of this set, S, then a subset of S is an exact cover of A if it exhaustively and exclu- sively partitions A. We provide a backtracking algorithm for solving ...

  9. Percent Wetland Cover (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be...

  10. Inclined-wall regular micro-pillar-arrayed surfaces covered entirely with an alumina nanowire forest and their improved superhydrophobicity

    International Nuclear Information System (INIS)

    Kim, Dae-Ho; Lee, Dongyun; Cho, Chae-Ryong; Kim, Soo-Hyung; Lee, Deug-Woo; Kim, Jong-Man; Kim, Yongsung; Kang, Jae-Wook; Hong, Suck Won

    2011-01-01

    This paper reports a multiple-scale hierarchically structured superhydrophobic surface that is composed of inclined-wall regular micro-pillar arrays covered entirely with an alumina nanowire forest (ANF) to improve the surface wettability. The multiple-scaled structures were fabricated stably using a simple batch process based on an anisotropic chemical silicon etching process and a subsequent time-controlled anodic aluminum oxide technique. The surface wetting properties of the mono-roughened surfaces with inclined-wall micro-pillar arrays, which are normally in the Wenzel wetting regime, could be transitioned perfectly to the slippery Cassie mode and enhanced greatly in the Wenzel regime in cases of a high- and low-density of the micro-pillars, respectively, by easily amplifying the intrinsic contact angle through the entire coverage of the ANF on the micro-roughened surfaces. The wettability of the proposed multiple-scaled surfaces could also be predicted using analytic surface models and the experimental results agreed greatly with the wetting trends estimated theoretically due to the geometrical regularity of the base micro-structures

  11. Finite cover method with mortar elements for elastoplasticity problems

    Science.gov (United States)

    Kurumatani, M.; Terada, K.

    2005-06-01

    Finite cover method (FCM) is extended to elastoplasticity problems. The FCM, which was originally developed under the name of manifold method, has recently been recognized as one of the generalized versions of finite element methods (FEM). Since the mesh for the FCM can be regular and squared regardless of the geometry of structures to be analyzed, structural analysts are released from a burdensome task of generating meshes conforming to physical boundaries. Numerical experiments are carried out to assess the performance of the FCM with such discretization in elastoplasticity problems. Particularly to achieve this accurately, the so-called mortar elements are introduced to impose displacement boundary conditions on the essential boundaries, and displacement compatibility conditions on material interfaces of two-phase materials or on joint surfaces between mutually incompatible meshes. The validity of the mortar approximation is also demonstrated in the elastic-plastic FCM.

  12. Silica-covered star-shaped Au-Ag nanoparticles as new electromagnetic nanoresonators for Raman characterisation of surfaces

    Science.gov (United States)

    Krajczewski, Jan; Kołątaj, Karol; Pietrasik, Sylwia; Kudelski, Andrzej

    2018-03-01

    One of the tools used for determining the composition of surfaces of various materials is shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). SHINERS is a modification of "standard" surface-enhanced Raman spectroscopy (SERS), in which, before Raman spectra are recorded, the surfaces analysed are covered with a layer of plasmonic nanoparticles protected by a very thin layer of a transparent dielectric. The plasmonic cores of the core-shell nanoparticles used in SHINERS measurements generate a local enhancement of the electric field of the incident electromagnetic radiation, whereas the transparent coatings prevent the metal cores from coming into direct contact with the material being analysed. In this contribution, we propose a new type of SHINERS nanoresonators that contain spiky, star-shaped metal cores (produced from a gold/silver alloy). These spiky, star-shaped Au-Ag nanoparticles have been covered by a layer of silica. The small radii of the ends of the tips of the spikes of these plasmonic nanostructures make it possible to generate a very large enhancement of the electromagnetic field there, with the result that such SHINERS nanoresonators are significantly more efficient than the standard semi-spherical nanostructures. The Au-Ag alloy nanoparticles were synthesised by the reduction of a solution containing silver nitrate and chloroauric acid by ascorbic acid. The final geometry of the nanostructures thus formed was controlled by changing the ratio between the concentrations of AuCl4- and Ag+ ions. The shape of the synthesised star-shaped Au-Ag nanoparticles does not change significantly during the two standard procedures for depositing a layer of silica (by the decomposition of sodium silicate or the decomposition of tetraethyl orthosilicate).

  13. Is Eurasian October snow cover extent increasing?

    International Nuclear Information System (INIS)

    Brown, R D; Derksen, C

    2013-01-01

    A number of recent studies present evidence of an increasing trend in Eurasian snow cover extent (SCE) in the October snow onset period based on analysis of the National Oceanic and Atmospheric Administration (NOAA) historical satellite record. These increases are inconsistent with fall season surface temperature warming trends across the region. Using four independent snow cover data sources (surface observations, two reanalyses, satellite passive microwave retrievals) we show that the increasing SCE is attributable to an internal trend in the NOAA CDR dataset to chart relatively more October snow cover extent over the dataset overlap period (1982–2005). Adjusting the series for this shift results in closer agreement with other independent datasets, stronger correlation with continentally-averaged air temperature anomalies, and a decrease in SCE over 1982–2011 consistent with surface air temperature warming trends over the same period. (letter)

  14. Land Surface Phenology from MODIS: Characterization of the Collection 5 Global Land Cover Dynamics Product

    Science.gov (United States)

    Ganguly, Sangram; Friedl, Mark A.; Tan, Bin; Zhang, Xiaoyang; Verma, Manish

    2010-01-01

    Information related to land surface phenology is important for a variety of applications. For example, phenology is widely used as a diagnostic of ecosystem response to global change. In addition, phenology influences seasonal scale fluxes of water, energy, and carbon between the land surface and atmosphere. Increasingly, the importance of phenology for studies of habitat and biodiversity is also being recognized. While many data sets related to plant phenology have been collected at specific sites or in networks focused on individual plants or plant species, remote sensing provides the only way to observe and monitor phenology over large scales and at regular intervals. The MODIS Global Land Cover Dynamics Product was developed to support investigations that require regional to global scale information related to spatiotemporal dynamics in land surface phenology. Here we describe the Collection 5 version of this product, which represents a substantial refinement relative to the Collection 4 product. This new version provides information related to land surface phenology at higher spatial resolution than Collection 4 (500-m vs. 1-km), and is based on 8-day instead of 16-day input data. The paper presents a brief overview of the algorithm, followed by an assessment of the product. To this end, we present (1) a comparison of results from Collection 5 versus Collection 4 for selected MODIS tiles that span a range of climate and ecological conditions, (2) a characterization of interannual variation in Collections 4 and 5 data for North America from 2001 to 2006, and (3) a comparison of Collection 5 results against ground observations for two forest sites in the northeastern United States. Results show that the Collection 5 product is qualitatively similar to Collection 4. However, Collection 5 has fewer missing values outside of regions with persistent cloud cover and atmospheric aerosols. Interannual variability in Collection 5 is consistent with expected ranges of

  15. Snow cover as a source of technogenic pollution of surface water during the snow melting period

    OpenAIRE

    Labuzova Olga; Noskova Tatyana; Lysenko Maria; Ovcharenko Elena; Papina Tatyana

    2016-01-01

    The study of pollutants in melt water of snow cover and snow disposal sites in the city of Barnaul showed that during the snow melting period the surface water is not subjected to significant technogenic impact according to a number of studied indices. The oils content is an exception: it can exceed MAC more than 20 times in river- water due to the melting of city disposal sites. Environmental damage due to an oils input into water resources during the snow melting period...

  16. THE STRUCTURE OF SURFACE H{sub 2}O LAYERS OF ICE-COVERED PLANETS WITH HIGH-PRESSURE ICE

    Energy Technology Data Exchange (ETDEWEB)

    Ueta, S.; Sasaki, T., E-mail: ueta@geo.titech.ac.jp, E-mail: takanori@geo.titech.ac.jp [Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2013-10-01

    Many extrasolar (bound) terrestrial planets and free-floating (unbound) planets have been discovered. While the existence of bound and unbound terrestrial planets with liquid water is an important question, of particular importance is the question of these planets' habitability. Even for a globally ice-covered planet, geothermal heat from the planetary interior may melt the interior ice, creating an internal ocean covered by an ice shell. In this paper, we discuss the conditions that terrestrial planets must satisfy for such an internal ocean to exist on the timescale of planetary evolution. The question is addressed in terms of planetary mass, distance from a central star, water abundance, and abundance of radiogenic heat sources. In addition, we investigate the structure of the surface H{sub 2}O layers of ice-covered planets by considering the effects of ice under high pressure (high-pressure ice). As a fiducial case, a 1 M{sub ⊕} planet at 1 AU from its central star and with 0.6-25 times the H{sub 2}O mass of the Earth could have an internal ocean. We find that high-pressure ice layers may appear between the internal ocean and the rock portion on a planet with an H{sub 2}O mass over 25 times that of the Earth. The planetary mass and abundance of surface water strongly restrict the conditions under which an extrasolar terrestrial planet may have an internal ocean with no high-pressure ice under the ocean. Such high-pressure ice layers underlying the internal ocean are likely to affect the habitability of the planet.

  17. Short-term contributions of cover crop surface residue return to soil carbon and nitrogen contents in temperate Australia.

    Science.gov (United States)

    Zhou, Xiaoqi; Wu, Hanwen; Li, Guangdi; Chen, Chengrong

    2016-11-01

    Cover crop species are usually grown to control weeds. After cover crop harvest, crop residue is applied on the ground to improve soil fertility and crop productivity. Little information is available about quantifying the contributions of cover crop application to soil total carbon (C) and nitrogen (N) contents in temperate Australia. Here, we selected eight cover crop treatments, including two legume crops (vetch and field pea), four non-legume crops (rye, wheat, Saia oat, and Indian mustard), a mixture of rye and vetch, and a nil-crop control in temperate Australia to calculate the contributions of cover crops (crop growth + residue decomposition) to soil C and N contents. Cover crops were sown in May 2009 (autumn). After harvest, the crop residue was placed on the soil surface in October 2009. Soil and crop samples were collected in October 2009 after harvest and in May 2010 after 8 months of residue decomposition. We examined cover crop residue biomass, soil and crop total C and N contents, and soil microbial biomass C and N contents. The results showed that cover crop application increased the mean soil total C by 187-253 kg ha -1 and the mean soil total N by 16.3-19.1 kg ha -1 relative to the nil-crop treatment, except for the mixture treatment, which had similar total C and N contents to the nil-crop control. Cover crop application increased the mean soil microbial biomass C by 15.5-20.9 kg ha -1 and the mean soil microbial biomass N by 4.5-10.2 kg ha -1 . We calculated the apparent percentage of soil total C derived from cover crop residue C losses and found that legume crops accounted for 10.6-13.9 %, whereas non-legume crops accounted for 16.4-18.4 % except for the mixture treatment (0.2 %). Overall, short-term cover crop application increased soil total C and N contents and microbial biomass C and N contents, which might help reduce N fertilizer use and improve sustainable agricultural development.

  18. Improved 2-D resistivity imaging of features in covered karst terrain with arrays of implanted electrodes

    Science.gov (United States)

    Kiflu, H. G.; Kruse, S. E.; Harro, D.; Loke, M. H.; Wilkinson, P. B.

    2013-12-01

    Electrical resistivity tomography is commonly used to identify geologic features associated with sinkhole formation. In covered karst terrain, however, it can be difficult to resolve the depth to top of limestone with this method. This is due to the fact that array lengths, and hence depth of resolution, are often limited by residential or commercial lot dimensions in urban environments. Furthermore, the sediments mantling the limestone are often clay-rich and highly conductive. The resistivity method has limited sensitivity to resistive zones beneath conductive zones. This sensitivity can be improved significantly with electrodes implanted at depth in the cover sediments near the top of limestone. An array of deep electrodes is installed with direct push technology in the karst cover. When combined with a surface array in which each surface electrode is underlain by a deep electrode, the array geometry is similar to a borehole array turned on its side. This method, called the Multi-Electrode Resistivity Implant Technique (MERIT), offers the promise of significantly improved resolution of epikarst and cover collapse development zones in the overlying sediment, the limestone or at the sediment-bedrock interface in heterogeneous karst environments. With a non-traditional array design, the question of optimal array geometries arises. Optimizing array geometries is complicated by the fact that many plausible 4-electrode readings will produce negative apparent resistivity values, even in homogeneous terrain. Negative apparent resistivities cannot be used in inversions based on the logarithm of the apparent resistivity. New algorithms for seeking optimal array geometries have been developed by modifying the 'Compare R' method of Wilkinson and Loke. The optimized arrays show significantly improved resolution over basic arrays adapted from traditional 2D surface geometries. Several MERIT case study surveys have been conducted in covered karst in west-central Florida, with

  19. Revegetation/rock cover for stabilization of inactive U-tailings sites

    International Nuclear Information System (INIS)

    Beedlow, P.A.; Cadwell, L.L.

    1982-01-01

    Soil placed over any sealant/barrier system can provide a protective mantle if the soil is not lost by erosion. Vegetation is an attractive choice for controlling erosion because it can provide an economic self-renewing cover that serves to reduce erosion by both wind and water. Vegetation alone, however, may not adequately stabilize the surface in extremely arid areas. In those areas, a properly designed surface treatment of rock cover, perhaps in conjunction with vegetation, may be necessary to stabilize the tailings surfaces. The objective of this program is to establish guidelines for surface stabilization that are compatible with sealant/barrier systems and that are suited to soils and climates at inactive uranium mill tailings sites. These guidelines will provide the means to estimate potential vegetation cover, potential erosion, effects of surface treatments on sealant/barrier systems, and costs of vegetation and rock covers. Methods for establishing vegetation on sealed tailings will also be provided

  20. Silica-covered star-shaped Au-Ag nanoparticles as new electromagnetic nanoresonators for Raman characterisation of surfaces.

    Science.gov (United States)

    Krajczewski, Jan; Kołątaj, Karol; Pietrasik, Sylwia; Kudelski, Andrzej

    2018-03-15

    One of the tools used for determining the composition of surfaces of various materials is shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). SHINERS is a modification of "standard" surface-enhanced Raman spectroscopy (SERS), in which, before Raman spectra are recorded, the surfaces analysed are covered with a layer of plasmonic nanoparticles protected by a very thin layer of a transparent dielectric. The plasmonic cores of the core-shell nanoparticles used in SHINERS measurements generate a local enhancement of the electric field of the incident electromagnetic radiation, whereas the transparent coatings prevent the metal cores from coming into direct contact with the material being analysed. In this contribution, we propose a new type of SHINERS nanoresonators that contain spiky, star-shaped metal cores (produced from a gold/silver alloy). These spiky, star-shaped Au-Ag nanoparticles have been covered by a layer of silica. The small radii of the ends of the tips of the spikes of these plasmonic nanostructures make it possible to generate a very large enhancement of the electromagnetic field there, with the result that such SHINERS nanoresonators are significantly more efficient than the standard semi-spherical nanostructures. The Au-Ag alloy nanoparticles were synthesised by the reduction of a solution containing silver nitrate and chloroauric acid by ascorbic acid. The final geometry of the nanostructures thus formed was controlled by changing the ratio between the concentrations of AuCl 4 - and Ag + ions. The shape of the synthesised star-shaped Au-Ag nanoparticles does not change significantly during the two standard procedures for depositing a layer of silica (by the decomposition of sodium silicate or the decomposition of tetraethyl orthosilicate). Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations

    Science.gov (United States)

    Lamsal, Damodar; Fujita, Koji; Sakai, Akiko

    2017-12-01

    This study presents the geodetic mass balance of Kanchenjunga Glacier, one of the largest debris-covered glaciers in the easternmost Nepal Himalaya, which possesses a negative mass balance of -0.18 ± 0.17 m w.e. a-1 for the 1975-2010 study period, estimated using digital elevation models (DEMs) generated from Hexagon KH-9 and ALOS PRISM stereo images. Accurate DEMs, with a relative uncertainty of ±5.5 m, were generated from the intensive and manual editing of triangulated irregular network (TIN) models on a stereo MirrorTM/3D Monitor. The glacier ice-flow velocity field was also calculated using a feature-tracking method that was applied to two ALOS orthoimages taken in 2010. The elevation differences between the two DEMs highlight considerable surface lowering across the debris-covered area, and a slight thickening in the accumulation area of Kanchenjunga Glacier between 1975 and 2010. The magnitude and gradient of surface lowering are similar among the six glacier tributaries, even though they are situated at different elevations, which may reflect variations in the ice-flow velocity field. The pattern of surface lowering correlates well with the ice-flow velocity field over the debris-covered portion of the main tributary, suggesting that the glacier dynamics significantly affect surface lowering by altering the emergence velocity along the glacier, particularly in the compressive ablation area. Surface-lowering patterns partially correspond to the supraglacial pond area fraction of the glacier, with enhanced surface lowering observed in areas that possess a larger pond area fraction. These findings support the hypothesis that supraglacial ponds may intensify ice wastage and play a key role in the heterogeneous surface lowering of debris-covered glaciers. The estimated mass loss of Kanchenjunga Glacier is moderate compared with other debris-covered glaciers in neighboring Himalayan regions, which may be due to the lower pond area fraction of Kanchenjunga

  2. Nuclear reactor coolant and cover gas system

    International Nuclear Information System (INIS)

    George, J.A.; Redding, A.H.; Tower, S.N.

    1976-01-01

    A core cooling system is disclosed for a nuclear reactor of the type utilizing a liquid coolant with a cover gas above free surfaces of the coolant. The disclosed system provides for a large inventory of reactor coolant and a balanced low pressure cover gas arrangement. A flow restricting device disposed within a reactor vessel achieves a pressure of the cover gas in the reactor vessel lower than the pressure of the reactor coolant in the vessel. The low gas pressure is maintained over all free surfaces of the coolant in the cooling system including a coolant reservoir tank. Reactor coolant stored in the reservoir tank allows for the large reactor coolant inventory provided by the invention

  3. Optimal shortening of uniform covering arrays.

    Directory of Open Access Journals (Sweden)

    Jose Torres-Jimenez

    Full Text Available Software test suites based on the concept of interaction testing are very useful for testing software components in an economical way. Test suites of this kind may be created using mathematical objects called covering arrays. A covering array, denoted by CA(N; t, k, v, is an N × k array over [Formula: see text] with the property that every N × t sub-array covers all t-tuples of [Formula: see text] at least once. Covering arrays can be used to test systems in which failures occur as a result of interactions among components or subsystems. They are often used in areas such as hardware Trojan detection, software testing, and network design. Because system testing is expensive, it is critical to reduce the amount of testing required. This paper addresses the Optimal Shortening of Covering ARrays (OSCAR problem, an optimization problem whose objective is to construct, from an existing covering array matrix of uniform level, an array with dimensions of (N - δ × (k - Δ such that the number of missing t-tuples is minimized. Two applications of the OSCAR problem are (a to produce smaller covering arrays from larger ones and (b to obtain quasi-covering arrays (covering arrays in which the number of missing t-tuples is small to be used as input to a meta-heuristic algorithm that produces covering arrays. In addition, it is proven that the OSCAR problem is NP-complete, and twelve different algorithms are proposed to solve it. An experiment was performed on 62 problem instances, and the results demonstrate the effectiveness of solving the OSCAR problem to facilitate the construction of new covering arrays.

  4. Impacts of Land Cover Changes on Climate over China

    Science.gov (United States)

    Chen, L.; Frauenfeld, O. W.

    2014-12-01

    Land cover changes can influence regional climate through modifying the surface energy balance and water fluxes, and can also affect climate at large scales via changes in atmospheric general circulation. With rapid population growth and economic development, China has experienced significant land cover changes, such as deforestation, grassland degradation, and farmland expansion. In this study, the Community Earth System Model (CESM) is used to investigate the climate impacts of anthropogenic land cover changes over China. To isolate the climatic effects of land cover change, we focus on the CAM and CLM models, with prescribed climatological sea surface temperature and sea ice cover. Two experiments were performed, one with current vegetation and the other with potential vegetation. Current vegetation conditions were derived from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations, and potential vegetation over China was obtained from Ramankutty and Foley's global potential vegetation dataset. Impacts of land cover changes on surface air temperature and precipitation are assessed based on the difference of the two experiments. Results suggest that land cover changes have a cold-season cooling effect in a large region of China, but a warming effect in summer. These temperature changes can be reconciled with albedo forcing and evapotranspiration. Moreover, impacts on atmospheric circulation and the Asian Monsoon is also discussed.

  5. Cover-layer with High Refractive Index for Near-Field Recording Media

    Science.gov (United States)

    Kim, Jin-Hong; Lee, Jun-Seok

    2007-06-01

    TiO2 nanoparticles are added into UV-curable resin to increase the refractive index of the cover-layer laminated for cover-layer incident near-field recording media. A high refractive index is required for the cover-layer operating with an optical head with a high numerical aperture. The eye pattern from a cover-layer coated 20 GB read-only memory disc in which the refractive index of the cover-layer is 1.75 is achieved, but the gap servo is unstable owing to the rough surface of the cover-layer. Even though the light loss due to the nanoparticles is negligible, a rough microstructure is developed by adding the nanoparticles into an organic binder material. To achieve a smooth surface for a stable gap servo, the solubility of the nanoparticles should be enhanced by the optimization of the surface of the nanoparticles.

  6. The adsorption of NO on an oxygen pre-covered Pt(1 1 1) surface: in situ high-resolution XPS combined with molecular beam studies

    Science.gov (United States)

    Zhu, J. F.; Kinne, M.; Fuhrmann, T.; Tränkenschuh, B.; Denecke, R.; Steinrück, H.-P.

    2003-12-01

    Adsorption of NO on a Pt(1 1 1) surface pre-covered with a p(2 × 2) atomic oxygen layer has been studied in situ by high-resolution X-ray photoelectron spectroscopy and temperature-programmed XPS using third-generation synchrotron radiation at BESSY II, Berlin, combined with molecular beam techniques and ex situ by low energy electron diffraction and temperature-programmed desorption. O 1s XP spectra reveal that an ordered p(2 × 2)-O layer dramatically changes the adsorption behavior of NO as compared to the clean surface. The atomic oxygen occupies fcc hollow sites, and therefore blocks NO adsorption on these sites, which are energetically preferred on clean Pt(1 1 1). As a consequence, NO populates on-top sites at low coverage. At 110 K for higher coverages, NO can additionally adsorb on hcp hollow sites, thereby inducing a shift of the O 1s binding energy of atomic oxygen towards lower energies by about 0.25 eV. The bond strength of the hcp hollow NO species to the substrate is weakened by the presence of atomic oxygen. A sharp p(2 × 2) LEED pattern is observed for NO adsorption on the oxygen pre-covered surface, up to saturation coverage. The total saturation coverage of NO on Pt(1 1 1) pre-covered with varying amounts of oxygen (below 0.25 ML) decreases linearly with the coverage of oxygen. The initial sticking coefficient of NO is reduced from 0.96 on clean Pt(1 1 1) to 0.88 on a p(2 × 2) oxygen pre-covered surface.

  7. Conceptual design of covering method for the proposed LILW near-surface repository at Cernavoda

    International Nuclear Information System (INIS)

    Diaconu, Daniela

    2003-01-01

    The disposal concept of the low and intermediate level (LIL) wastes resulting during NPP operation combines both the natural and engineered barriers in order to ensure the safety of the environment and population. Saligny site has been proposed for LIL waste disposal. Preliminary performance assessments indicate that the loess and clay layers are efficient natural barriers against water flow and radionuclide migration through the vadose zone to the local aquifers. At present, the studies on site characterization are concentrated on investigation of the potential factors affecting the long-term integrity of the disposal facility. This analysis showed that surface erosion by wind and water and bio-intrusion by plant roots and burrowing animals could affect the long-term disposal safety. Based on the preliminary erosion results, as well as on the high probability of bio-intrusion by the plant roots and burrowing animals (i.e. moles, mice), different covering systems able to ensure the long-term safety of the repository has been proposed and analyzed. FEHM and HYDRUS 2D water flow simulations have been performed in order to compare their efficiency in the diminution of the infiltration rate in the repository. From this point of view, the covering system combining the capillary barrier and the resistive layer proved to have the best behavior

  8. Snow cover as a source of technogenic pollution of surface water during the snow melting period

    Directory of Open Access Journals (Sweden)

    Labuzova Olga

    2016-10-01

    Full Text Available The study of pollutants in melt water of snow cover and snow disposal sites in the city of Barnaul showed that during the snow melting period the surface water is not subjected to significant technogenic impact according to a number of studied indices. The oils content is an exception: it can exceed MAC more than 20 times in river- water due to the melting of city disposal sites. Environmental damage due to an oils input into water resources during the snow melting period can be more than 300000 thousand rubles.

  9. Water Induced Surface Reconstruction of the Oxygen (2x1) covered Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Sabine; Cabrera-Sanfelix, Pepa; Stass, Ingeborg; Sanchez-Portal, Daniel; Arnau, Andres; Salmeron, Miquel

    2010-08-06

    Low temperature scanning tunneling microscopy (STM) and density functional theory (DFT) were used to study the adsorption of water on a Ru(0001) surface covered with half monolayer of oxygen. The oxygen atoms occupy hcp sites in an ordered structure with (2x1) periodicity. DFT predicts that water is weakly bound to the unmodified surface, 86 meV compared to the ~;;200 meV water-water H-bond. Instead, we found that water adsorption causes a shift of half of the oxygen atoms from hcp sites to fcc sites, creating a honeycomb structure where water molecules bind strongly to the exposed Ru atoms. The energy cost of reconstructing the oxygen overlayer, around 230 meV per displaced oxygen atom, is more than compensated by the larger adsorption energy of water on the newly exposed Ru atoms. Water forms hydrogen bonds with the fcc O atoms in a (4x2) superstructure due to alternating orientations of the molecules. Heating to 185 K results in the complete desorption of the water layer, leaving behind the oxygen honeycomb structure, which is metastable relative to the original (2x1). This stable structure is not recovered until after heating to temperatures close to 260K.

  10. Call for volunteers

    CERN Document Server

    2008-01-01

    CERN is calling for volunteers from all members of the Laboratory for organizing the two exceptional Open days.CERN is calling for volunteers from all members of the Laboratory’s personnel to help with the organisation of these two exceptional Open Days, for the visits of CERN personnel and their families on the Saturday and above all for the major public Open Day on the Sunday. As for the 50th anniversary in 2004, the success of the Open Days will depend on a large number of volunteers. All those working for CERN as well as retired members of the personnel can contribute to making this event a success. Many guides will be needed at the LHC points, for the activities at the surface and to man the reception and information points. The aim of these major Open Days is to give the local populations the opportunity to discover the fruits of almost 20 years of work carried out at CERN. We are hoping for some 2000 volunteers for the two Open Days, on the Saturday from 9 a.m. to ...

  11. Land cover mapping of North and Central America—Global Land Cover 2000

    Science.gov (United States)

    Latifovic, Rasim; Zhu, Zhi-Liang

    2004-01-01

    The Land Cover Map of North and Central America for the year 2000 (GLC 2000-NCA), prepared by NRCan/CCRS and USGS/EROS Data Centre (EDC) as a regional component of the Global Land Cover 2000 project, is the subject of this paper. A new mapping approach for transforming satellite observations acquired by the SPOT4/VGTETATION (VGT) sensor into land cover information is outlined. The procedure includes: (1) conversion of daily data into 10-day composite; (2) post-seasonal correction and refinement of apparent surface reflectance in 10-day composite images; and (3) extraction of land cover information from the composite images. The pre-processing and mosaicking techniques developed and used in this study proved to be very effective in removing cloud contamination, BRDF effects, and noise in Short Wave Infra-Red (SWIR). The GLC 2000-NCA land cover map is provided as a regional product with 28 land cover classes based on modified Federal Geographic Data Committee/Vegetation Classification Standard (FGDC NVCS) classification system, and as part of a global product with 22 land cover classes based on Land Cover Classification System (LCCS) of the Food and Agriculture Organisation. The map was compared on both areal and per-pixel bases over North and Central America to the International Geosphere–Biosphere Programme (IGBP) global land cover classification, the University of Maryland global land cover classification (UMd) and the Moderate Resolution Imaging Spectroradiometer (MODIS) Global land cover classification produced by Boston University (BU). There was good agreement (79%) on the spatial distribution and areal extent of forest between GLC 2000-NCA and the other maps, however, GLC 2000-NCA provides additional information on the spatial distribution of forest types. The GLC 2000-NCA map was produced at the continental level incorporating specific needs of the region.

  12. Such membranes are called “D2-branes”.

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Such membranes are called “D2-branes”. D is for “Dirichlet”, the boundary conditions which fix the ends of open strings onto a surface. 2 is for a 2-dimensional surface, a membrane. So we say that open string theory has D2-branes among its excitations. Notes:

  13. Debris thickness patterns on debris-covered glaciers

    Science.gov (United States)

    Anderson, Leif S.; Anderson, Robert S.

    2018-06-01

    Many debris-covered glaciers have broadly similar debris thickness patterns: surface debris thickens and tends to transition from convex- to concave-up-down glacier. We explain this pattern using theory (analytical and numerical models) paired with empirical observations. Down glacier debris thickening results from the conveyor-belt-like nature of the glacier surface in the ablation zone (debris can typically only be added but not removed) and from the inevitable decline in ice surface velocity toward the terminus. Down-glacier thickening of debris leads to the reduction of sub-debris melt and debris emergence toward the terminus. Convex-up debris thickness patterns occur near the up-glacier end of debris covers where debris emergence dominates (ablation controlled). Concave-up debris thickness patterns occur toward glacier termini where declining surface velocities dominate (velocity controlled). A convex-concave debris thickness profile inevitably results from the transition between ablation-control and velocity-control down-glacier. Debris thickness patterns deviating from this longitudinal shape are most likely caused by changes in hillslope debris supply through time. By establishing this expected debris thickness pattern, the effects of climate change on debris cover can be better identified.

  14. A cross-site vascular radiology on-call service: the Manchester experience

    International Nuclear Information System (INIS)

    Ashleigh, R.J.; Butterfield, J.S.; Asquith, J.; Chalmers, N.; Murphy, G.

    2005-01-01

    AIM: A cross-site vascular radiology on-call service was established 5 years ago to cover two vascular centres in Manchester. We aimed to review the service. MATERIALS AND METHODS: A prospective audit of out-of hours referrals and procedures over a three month period (March-May 2003) was undertaken. RESULTS: There were 52 incidents in 49 patients (mean 4 calls per week). Nine involved telephone advice only, the remainder (82%) required a procedure. Angiography was performed on 88% of patients and therapeutic radiological intervention on 50%. 71% of calls occurred at a weekend. 50% of the calls were from vascular surgery and 50% from other sources. The consultant vascular radiologist was present for 93% of procedures. CONCLUSIONS: The workload suggests that a vascular radiology on call service is justified in Manchester. There have been no major problems with its implementation and operation. This is a consultant led service, with very few cases being devolved to a specialist registrar (SpR)

  15. Patient Handoffs: Is Cross Cover or Night Shift Better?

    Science.gov (United States)

    Higgins, Alanna; Brannen, Melissa L; Heiman, Heather L; Adler, Mark D

    2017-06-01

    Studies show singular handoffs between health care providers to be risky. Few describe sequential handoffs or compare handoffs from different provider types. We investigated the transfer of information across 2 handoffs using a piloted survey instrument. We compared cross-cover (every fourth night call) with dedicated night-shift residents. Surveys assessing provider knowledge of hospitalized patients were administered to pediatric residents. Primary teams were surveyed about their handoff upon completion of daytime coverage of a patient. Night-shift or cross-covering residents were surveyed about their handoff of the same patient upon completion of overnight coverage. Pediatric hospitalists rated the consistency of information between the surveys. Absolute difference was calculated between the 2 providers' rating of a patient's (a) complexity and (b) illness severity. Scores were compared across provider type. Fifty-nine complete handoff pairs were obtained. Fourteen and 45 handoff surveys were completed by a cross-covering and a night-shift provider, respectively. There was no significant difference in information consistency between primary and night-shift (median, 4.0; interquartile range [IQR], 3-4) versus primary and cross-covering providers (median, 4.0; IQR, 3-4). There was no significant difference in median patient complexity ratings (night shift, 3.0; IQR, 1-5, versus cross cover, 3.5; IQR, 1-5) or illness severity ratings (night shift, 2.0; IQR, 1-4, versus cross-cover, 3.0; IQR, 1-6) when comparing provider types giving a handoff. We did not find a difference in physicians' transfer of information during 2 handoffs among providers taking traditional call or on night shift. Development of tools to measure handoff consistency is needed.

  16. Interactive Design and Visualization of Branched Covering Spaces.

    Science.gov (United States)

    Roy, Lawrence; Kumar, Prashant; Golbabaei, Sanaz; Zhang, Yue; Zhang, Eugene

    2018-01-01

    Branched covering spaces are a mathematical concept which originates from complex analysis and topology and has applications in tensor field topology and geometry remeshing. Given a manifold surface and an -way rotational symmetry field, a branched covering space is a manifold surface that has an -to-1 map to the original surface except at the ramification points, which correspond to the singularities in the rotational symmetry field. Understanding the notion and mathematical properties of branched covering spaces is important to researchers in tensor field visualization and geometry processing, and their application areas. In this paper, we provide a framework to interactively design and visualize the branched covering space (BCS) of an input mesh surface and a rotational symmetry field defined on it. In our framework, the user can visualize not only the BCSs but also their construction process. In addition, our system allows the user to design the geometric realization of the BCS using mesh deformation techniques as well as connecting tubes. This enables the user to verify important facts about BCSs such as that they are manifold surfaces around singularities, as well as the Riemann-Hurwitz formula which relates the Euler characteristic of the BCS to that of the original mesh. Our system is evaluated by student researchers in scientific visualization and geometry processing as well as faculty members in mathematics at our university who teach topology. We include their evaluations and feedback in the paper.

  17. Soil chemical and physical properties that differentiate urban land-use and cover types

    Science.gov (United States)

    R.V. Pouyat; I.D. Yesilonis; J. Russell-Anelli; N.K. Neerchal

    2007-01-01

    We investigated the effects of land use and cover and surface geology on soil properties in Baltimore, MD, with the objectives to: (i) measure the physical and chemical properties of surface soils (0?10 cm) by land use and cover; and (ii) ascertain whether land use and cover explain differences in these properties relative to surface geology. Mean and median values of...

  18. Structure of the surface of the Paleozoic basement of the cis-Kopetdag trough in connection with the oil and gas content of the sedimentary cover

    Energy Technology Data Exchange (ETDEWEB)

    Odekov, O.A.; Mel' nik, N.M.; Tulaeva, S.V.

    1981-01-01

    Use of a complex of different methods permitted a new approach to the study of the nature of the surface of the Paleozoic basement. As a result of constructing models of the deep structure of the cis-Kopetdag trough and the Bakhardok monocline a new map of the major tectonic elements of the region has been developed and a map of the surface structure of the Paleozoic basement and a map of the Moho discontinuity have been compiled. The former gives a major new solution to many problems of the dep structure of the region: 1) in the zone of juncture of the cis-Kopetdag trough and the Bakhardok monocline a new positive structural element has been identified, called the Bakhardok-Kumbet buried superarch; 2) a completely new morphology of the western part of the Serakh connector has been given, within which two independent buried arches are identified, the Shatlyk and Tedzhenskii; 3) it has been established that the Izgantskii arch of the sedimentary cover corresponds to the Izgant uplifted block of the basement. These structural elements are described, methods for identifying them are outlined, and some principles of the variatin of the parameters of the geophysical fields are described. The prospects for the juncture zone are estimated as fairly high from the viewpoint of discovering different types of oil and gas deposits in the widest stratigraphic interval, from the Lower Jurassic to the Neokomian.

  19. Coverings and the fundamental group for partial differential equations

    NARCIS (Netherlands)

    Igonin, S.

    2003-01-01

    Following I. S. Krasilshchik and A. M. Vinogradov, we regard systems of PDEs as manifolds with involutive distributions and consider their special morphisms called differential coverings, which include constructions like Lax pairs and B\\"acklund transformations in soliton theory. We show that,

  20. Photoemission studies of clean and adsorbate covered metal surfaces using synchrotron and uv radiation sources

    International Nuclear Information System (INIS)

    Apai, G.R. II.

    1977-09-01

    Photoemission energy distribution experiments on clean metal and adsorbate-covered surfaces were performed under ultrahigh vacuum conditions by using x-ray and ultraviolet photon sources in the laboratory as well as continuously-tunable, highly polarized synchrotron radiation obtainable at the Stanford Synchrotron Radiation Laboratory (SSRL). Studies focused on two general areas: cross-section modulation in the photoemission process was studied as a function of photon energy and orbital composition. Sharp decreases in intensity of the valence bands of several transition metals (i.e., Ag, Au, and Pt) are attributed to the radial nodes in the respective wave functions. Adsorbate photoemission studies of CO adsorbed on platinum single crystals have demonstrated a very high spectral sensitivity to the 4sigma and (1π + 5sigma) peaks of CO at photon energies of 150 eV. Angle-resolved photoemission allowed determination of the orientation of CO chemisorbed on a Pt (111) or Ni(111) surface. Prelinimary results at high photon energies (approximately 150 eV) indicated scattering from the substrate which could yield chemisorption site geometries

  1. Effects of vegetation and soil-surface cover treatments on the hydrologic behavior of low-level waste trench caps

    International Nuclear Information System (INIS)

    Lopez, E.A.; Barnes, F.J.; Antonio, E.J.

    1988-01-01

    Preliminary results are presented on a three-year field study at Los Alamos National Laboratory to evaluate the influence of different low-level radioactive waste trench cap designs on water balance under natural precipitation. Erosion plots having two different vegetative covers (shrubs and grasses) and with either gravel-mulched or unmulched soil surface treatments have been established on three different soil profiles on a decommissioned waste site. Total runoff and soil loss from each plot is measured after each precipitation event. Soil moisture is measured biweekly while plant canopy cover is measured seasonally. Preliminary results from the first year show that the application of a gravel mulch reduced runoff by 73 to 90%. Total soil loss was reduced by 83 to 93% by the mulch treatment. On unmulched plots, grass cover reduced both runoff and soil loss by about 50% compared to the shrub plots. Continued monitoring of the study site will provide data that will be used to analyze complex interactions between independent variables such rainfall amount and intensity, antecedent soil moisture, and soil and vegetation factors, as they influence water balance, and soil erosion. 18 refs., 2 figs., 3 tabs

  2. Impact of satellite-based lake surface observations on the initial state of HIRLAM. Part II: Analysis of lake surface temperature and ice cover

    Directory of Open Access Journals (Sweden)

    Homa Kheyrollah Pour

    2014-09-01

    Full Text Available This paper presents results from a study on the impact of remote-sensing Lake Surface Water Temperature (LSWT observations in the analysis of lake surface state of a numerical weather prediction (NWP model. Data assimilation experiments were performed with the High Resolution Limited Area Model (HIRLAM, a three-dimensional operational NWP model. Selected thermal remote-sensing LSWT observations provided by the Moderate Resolution Imaging Spectroradiometer (MODIS and Advanced Along-Track Scanning Radiometer (AATSR sensors onboard the Terra/Aqua and ENVISAT satellites, respectively, were included into the assimilation. The domain of our experiments, which focussed on two winters (2010–2011 and 2011–2012, covered northern Europe. Validation of the resulting objective analyses against independent observations demonstrated that the description of the lake surface state can be improved by the introduction of space-borne LSWT observations, compared to the result of pure prognostic parameterisations or assimilation of the available limited number of in-situ lake temperature observations. Further development of the data assimilation methods and solving of several practical issues are necessary in order to fully benefit from the space-borne observations of lake surface state for the improvement of the operational weather forecast. This paper is the second part of a series of two papers aimed at improving the objective analysis of lake temperature and ice conditions in HIRLAM.

  3. Climatological determinants of woody cover in Africa.

    Science.gov (United States)

    Good, Stephen P; Caylor, Kelly K

    2011-03-22

    Determining the factors that influence the distribution of woody vegetation cover and resolving the sensitivity of woody vegetation cover to shifts in environmental forcing are critical steps necessary to predict continental-scale responses of dryland ecosystems to climate change. We use a 6-year satellite data record of fractional woody vegetation cover and an 11-year daily precipitation record to investigate the climatological controls on woody vegetation cover across the African continent. We find that-as opposed to a relationship with only mean annual rainfall-the upper limit of fractional woody vegetation cover is strongly influenced by both the quantity and intensity of rainfall events. Using a set of statistics derived from the seasonal distribution of rainfall, we show that areas with similar seasonal rainfall totals have higher fractional woody cover if the local rainfall climatology consists of frequent, less intense precipitation events. Based on these observations, we develop a generalized response surface between rainfall climatology and maximum woody vegetation cover across the African continent. The normalized local gradient of this response surface is used as an estimator of ecosystem vegetation sensitivity to climatological variation. A comparison between predicted climate sensitivity patterns and observed shifts in both rainfall and vegetation during 2009 reveals both the importance of rainfall climatology in governing how ecosystems respond to interannual fluctuations in climate and the utility of our framework as a means to forecast continental-scale patterns of vegetation shifts in response to future climate change.

  4. The Average Covering Tree Value for Directed Graph Games

    NARCIS (Netherlands)

    Khmelnitskaya, A.; Selcuk, O.; Talman, A.J.J.

    2012-01-01

    Abstract: We introduce a single-valued solution concept, the so-called average covering tree value, for the class of transferable utility games with limited communication structure represented by a directed graph. The solution is the average of the marginal contribution vectors corresponding to all

  5. Modelling the future of the arctic sea ice cover

    OpenAIRE

    Myklebust, Erik Bryhn

    2017-01-01

    Record lows in sea ice cover have recently sparked new interest in the small ice cap instability. The change in albedo when sea ice becomes open water introduces a nonlinearity called the ice-albedo feedback. Forcing a joint energy- balance and sea ice model can lead to unstable ice caps in certain parameter regimes. When the ice caps are unstable, a small perturbation will initiate a tipping point in the sea ice cover. For tipping points in general, a number of studies have pointed out that ...

  6. A Continental United States High Resolution NLCD Land Cover – MODIS Albedo Database to Examine Albedo and Land Cover Change Relationships

    Science.gov (United States)

    Surface albedo influences climate by affecting the amount of solar radiation that is reflected at the Earth’s surface, and surface albedo is, in turn, affected by land cover. General Circulation Models typically use modeled or prescribed albedo to assess the influence of land co...

  7. Improving patient care over weekends by reducing on-call work load and better time management.

    Science.gov (United States)

    Gardezi, Syed Anjum Ali

    2014-01-01

    The Royal College of Physicians states that "handover, particularly of temporary 'on-call' responsibility, has been identified as a point at which errors are likely to occur."[1] Working a weekend on-call covering medical wards is often busy and stressful for all junior doctors. The high volume of routine and unplanned tasks make the situation even worse. In Nevill Hall hospital Abergavenny, we measured the workload on a junior doctor for medical ward cover on weekends by counting the number of times he/she was bleeped for routine tasks. Initial study demonstrated that on average 30-40% of time on a long day shift was spent on jobs which could have been done on the preceding Friday. The "FRIDAYS" checklist was introduced for clinical staff (particularly junior doctors) to identify these jobs. According to this model, all the junior doctors were encouraged to review: F: Phlebotomy R: Rewriting drug charts I: IV fluids D: discharge summaries A: Antibiotic review Y: Yellow book/Warfarin dose S: Status of resuscitation and escalation plans before leaving the wards on Friday afternoon. This implementation successfully showed reduction in weekend workload, allowing the ward cover to be focused on care and safety of comparatively sick patients while at the same time reducing the stress for the on-call team.

  8. The Impact of Time Difference between Satellite Overpass and Ground Observation on Cloud Cover Performance Statistics

    Directory of Open Access Journals (Sweden)

    Jędrzej S. Bojanowski

    2014-12-01

    Full Text Available Cloud property data sets derived from passive sensors onboard the polar orbiting satellites (such as the NOAA’s Advanced Very High Resolution Radiometer have global coverage and now span a climatological time period. Synoptic surface observations (SYNOP are often used to characterize the accuracy of satellite-based cloud cover. Infrequent overpasses of polar orbiting satellites combined with the 3- or 6-h SYNOP frequency lead to collocation time differences of up to 3 h. The associated collocation error degrades the cloud cover performance statistics such as the Hanssen-Kuiper’s discriminant (HK by up to 45%. Limiting the time difference to 10 min, on the other hand, introduces a sampling error due to a lower number of corresponding satellite and SYNOP observations. This error depends on both the length of the validated time series and the SYNOP frequency. The trade-off between collocation and sampling error call for an optimum collocation time difference. It however depends on cloud cover characteristics and SYNOP frequency, and cannot be generalized. Instead, a method is presented to reconstruct the unbiased (true HK from HK affected by the collocation differences, which significantly (t-test p < 0.01 improves the validation results.

  9. Analysis of radon protection cover on uranium tailings pile

    International Nuclear Information System (INIS)

    Zhang Zhe

    1993-01-01

    The average radon emanation rate of the whole surface over one year was used for evaluating the radon release of uranium tailings pile. The effective of radon protection cover depends on the shape and property of the tailings pile, the properties of covering and the control of air vadose in the pile. It was indicated that the covering with low diffusion coefficient, small porosity and bad permeability was suitable to cover the pile. The analytical formula of the covering layer thickness was given

  10. Climate Impacts of Cover Crops

    Science.gov (United States)

    Lombardozzi, D.; Wieder, W. R.; Bonan, G. B.; Morris, C. K.; Grandy, S.

    2016-12-01

    Cover crops are planted in agricultural rotation with the intention of protecting soil rather than harvest. Cover crops have numerous environmental benefits that include preventing soil erosion, increasing soil fertility, and providing weed and pest control- among others. In addition to localized environmental benefits, cover crops can have important regional or global biogeochemical impacts by increasing soil organic carbon, changing emissions of greenhouse trace gases like nitrous oxide and methane, and reducing hydrologic nitrogen losses. Cover crops may additionally affect climate by changing biogeophysical processes, like albedo and latent heat flux, though these potential changes have not yet been evaluated. Here we use the coupled Community Atmosphere Model (CAM5) - Community Land Model (CLM4.5) to test how planting cover crops in the United States may change biogeophysical fluxes and climate. We present seasonal changes in albedo, heat fluxes, evaporative partitioning, radiation, and the resulting changes in temperature. Preliminary analyses show that during seasons when cover crops are planted, latent heat flux increases and albedo decreases, changing the evaporative fraction and surface temperatures. Understanding both the biogeophysical changes caused by planting cover crops in this study and the biogeochemical changes found in other studies will give a clearer picture of the overall impacts of cover crops on climate and atmospheric chemistry, informing how this land use strategy will impact climate in the future.

  11. Impact of Vegetation Cover Fraction Parameterization schemes on Land Surface Temperature Simulation in the Tibetan Plateau

    Science.gov (United States)

    Lv, M.; Li, C.; Lu, H.; Yang, K.; Chen, Y.

    2017-12-01

    The parameterization of vegetation cover fraction (VCF) is an important component of land surface models. This paper investigates the impacts of three VCF parameterization schemes on land surface temperature (LST) simulation by the Common Land Model (CoLM) in the Tibetan Plateau (TP). The first scheme is a simple land cover (LC) based method; the second one is based on remote sensing observation (hereafter named as RNVCF) , in which multi-year climatology VCFs is derived from Moderate-resolution Imaging Spectroradiometer (MODIS) NDVI (Normalized Difference Vegetation Index); the third VCF parameterization scheme derives VCF from the LAI simulated by LSM and clump index at every model time step (hereafter named as SMVCF). Simulated land surface temperature(LST) and soil temperature by CoLM with three VCF parameterization schemes were evaluated by using satellite LST observation and in situ soil temperature observation, respectively, during the period of 2010 to 2013. The comparison against MODIS Aqua LST indicates that (1) CTL produces large biases for both four seasons in early afternoon (about 13:30, local solar time), while the mean bias in spring reach to 12.14K; (2) RNVCF and SMVCF reduce the mean bias significantly, especially in spring as such reduce is about 6.5K. Surface soil temperature observed at 5 cm depth from three soil moisture and temperature monitoring networks is also employed to assess the skill of three VCF schemes. The three networks, crossing TP from West to East, have different climate and vegetation conditions. In the Ngari network, located in the Western TP with an arid climate, there are not obvious differences among three schemes. In Naqu network, located in central TP with a semi-arid climate condition, CTL shows a severe overestimates (12.1 K), but such overestimations can be reduced by 79% by RNVCF and 87% by SMVCF. In the third humid network (Maqu in eastern TP), CoLM performs similar to Naqu. However, at both Naqu and Maqu networks

  12. On the impact of snow cover on daytime pollution dispersion

    Science.gov (United States)

    Segal, M.; Garratt, J. R.; Pielke, R. A.; Hildebrand, P.; Rogers, F. A.; Cramer, J.; Schanot, A.

    A preliminary evaluation of the impact of snow cover on daytime pollutant dispersion conditions is made by using conceptual, scaling, and observational analyses. For uniform snow cover and synoptically unperturbed sunny conditions, observations indicate a considerate suppression of the surface sensible heat flux, the turbulence, and the development of the daytime atmospheric boundary layer (ABL) when compared to snow-free conditions. However, under conditions of non-uniform snow cover, as in urban areas, or associated with vegetated areas or bare ground patches, a milder effect on pollutant dispersion conditions would be expected. Observed concentrations of atmospheric particles within the ABL, and surface pollutant concentrations in urban areas, reflect the impact of snow cover on the modification of ABL characteristics.

  13. Overstory Structure and Surface Cover Dynamics in the Decade Following the Hayman Fire, Colorado

    Directory of Open Access Journals (Sweden)

    Paula J. Fornwalt

    2018-03-01

    Full Text Available The 2002 Hayman Fire burned with mixed-severity across a 400-ha dry conifer study site in Colorado, USA, where overstory tree and surface cover attributes had been recently measured on 20 0.1-ha permanent plots. We remeasured these plots repeatedly during the first post-fire decade to examine how the attributes changed through time and whether changes were influenced by fire severity. We found that most attributes were temporally dynamic and that fire severity shaped their dynamics. For example, low-severity plots experienced a modest reduction in live overstory density due to both immediate and delayed tree mortality, and no change in live overstory basal area through time; in contrast, high-severity plots experienced an immediate and total loss of live overstory density and basal area. Large snag density in low-severity plots did not vary temporally because snag recruitment balanced snag loss; however, in high-severity plots large snag density increased markedly immediately post-fire and then declined by about half by post-fire year ten as snags fell. Mineral soil cover increased modestly immediately post-fire in low-severity plots and substantially immediately post-fire in high-severity plots, but changed little in ensuing years for either severity class. By incorporating pre-fire and repeatedly-measured post-fire data for a range of severities, our study uniquely contributes to the current understanding of wildfire effects in dry conifer forests and should be of interest to managers, researchers, and others.

  14. Land cover classification using reformed fuzzy C-means

    Indian Academy of Sciences (India)

    This paper explains the task of land cover classification using reformed fuzzy C means. Clustering is the assignment of objects into groups called clusters so that objects from the same cluster are more similar to each other than objects from different clusters. The most basic attribute for clustering of an image is its luminance ...

  15. Analysis and modelling of surface Urban Heat Island in 20 Canadian cities under climate and land-cover change.

    Science.gov (United States)

    Gaur, Abhishek; Eichenbaum, Markus Kalev; Simonovic, Slobodan P

    2018-01-15

    Surface Urban Heat Island (SUHI) is an urban climate phenomenon that is expected to respond to future climate and land-use land-cover change. It is important to further our understanding of physical mechanisms that govern SUHI phenomenon to enhance our ability to model future SUHI characteristics under changing geophysical conditions. In this study, SUHI phenomenon is quantified and modelled at 20 cities distributed across Canada. By analyzing MODerate Resolution Imaging Spectroradiometer (MODIS) sensed surface temperature at the cities over 2002-2012, it is found that 16 out of 20 selected cities have experienced a positive SUHI phenomenon while 4 cities located in the prairies region and high elevation locations have experienced a negative SUHI phenomenon in the past. A statistically significant relationship between observed SUHI magnitude and city elevation is also recorded over the observational period. A Physical Scaling downscaling model is then validated and used to downscale future surface temperature projections from 3 GCMs and 2 extreme Representative Concentration Pathways in the urban and rural areas of the cities. Future changes in SUHI magnitudes between historical (2006-2015) and future timelines: 2030s (2026-2035), 2050s (2046-2055), and 2090s (2091-2100) are estimated. Analysis of future projected changes indicate that 15 (13) out of 20 cities can be expected to experience increases in SUHI magnitudes in future under RCP 2.6 (RCP 8.5). A statistically significant relationship between projected future SUHI change and current size of the cities is also obtained. The study highlights the role of city properties (i.e. its size, elevation, and surrounding land-cover) towards shaping their current and future SUHI characteristics. The results from this analysis will help decision-makers to manage Canadian cities more efficiently under rapidly changing geophysical and demographical conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Comprehensive Sexuality Education as a Longitudinal Predictor of LGBTQ Name-Calling and Perceived Willingness to Intervene in School.

    Science.gov (United States)

    Baams, Laura; Dubas, Judith Semon; van Aken, Marcel A G

    2017-05-01

    Comprehensive sexuality education and sexuality education that is inclusive to lesbian, gay, bisexual, transgender, queer, and questioning (LGBTQ) youth is thought to educate and support youth in their social relations. Despite the obligation for Dutch schools to cover sexuality education in their curricula, including the topic of sexual diversity, the content that is covered varies widely across schools. With the current study, we present an overview of the content of sexuality education as reported by a sample of 601 Dutch adolescents (58.4% female youth) from six different high schools (e.g., public, Roman Catholic, protestant, anthroposophical; grades 10-12). Further, we examine whether the content or extensiveness of sexuality education at the beginning of the school year is related to a decrease in LGBTQ name-calling and an increase in the willingness to intervene when witnessing LGBTQ name-calling at the end of the school year. Adolescents completed three surveys, spaced four months apart. The results show that anatomy, STI prevention, and relationships are covered most often in sexuality education, with less attention to sexual diversity. Our longitudinal findings show that having a wide variety of topics covered in sexuality education-not just sexual diversity-was related to an increase in perceived willingness to intervene when witnessing LGBTQ name-calling by teachers or school staff, fellow students, and youth themselves (female youth). It also predicted a decrease in the occurrence of name-calling according to females. Our findings emphasize the importance of having comprehensive sexuality education in schools; it not only educates and empowers youth but also signals a safer school climate.

  17. Using ASTER Imagery in Land Use/cover Classification of Eastern Mediterranean Landscapes According to CORINE Land Cover Project

    Directory of Open Access Journals (Sweden)

    Recep Gundogan

    2008-02-01

    Full Text Available The satellite imagery has been effectively utilized for classifying land covertypes and detecting land cover conditions. The Advanced Spaceborne Thermal Emissionand Reflection Radiometer (ASTER sensor imagery has been widely used in classificationprocess of land cover. However, atmospheric corrections have to be made by preprocessingsatellite sensor imagery since the electromagnetic radiation signals received by the satellitesensors can be scattered and absorbed by the atmospheric gases and aerosols. In this study,an ASTER sensor imagery, which was converted into top-of-atmosphere reflectance(TOA, was used to classify the land use/cover types, according to COoRdination ofINformation on the Environment (CORINE land cover nomenclature, for an arearepresenting the heterogonous characteristics of eastern Mediterranean regions inKahramanmaras, Turkey. The results indicated that using the surface reflectance data ofASTER sensor imagery can provide accurate (i.e. overall accuracy and kappa values of83.2% and 0.79, respectively and low-cost cover mapping as a part of inventory forCORINE Land Cover Project.

  18. Impact of land cover changes on the South African climate

    International Nuclear Information System (INIS)

    Ngwana, T I; Demory, M-E; Vidale, P L; Plant, R S; Mbedzi, M P

    2010-01-01

    The Joint UK Land Environmental Simulator (JULES) was run offline to investigate the sensitivity of land surface type changes over South Africa. Sensitivity tests were made in idealised experiments where the actual land surface cover is replaced by a single homogeneous surface type. The vegetation surface types on which some of the experiments were made are static. Experimental tests were evaluated against the control. The model results show among others that the change of the surface cover results in changes of other variables such as soil moisture, albedo, net radiation and etc. These changes are also visible in the spin up process. The model shows different surfaces spinning up at different cycles. Because JULES is the land surface model of Unified Model, the results could be more physically meaningful if it is coupled to the Unified Model.

  19. The managed clearing: An overlooked land-cover type in urbanizing regions?

    Science.gov (United States)

    Madden, Marguerite; Gray, Josh; Meentemeyer, Ross K.

    2018-01-01

    Urban ecosystem assessments increasingly rely on widely available map products, such as the U.S. Geological Service (USGS) National Land Cover Database (NLCD), and datasets that use generic classification schemes to detect and model large-scale impacts of land-cover change. However, utilizing existing map products or schemes without identifying relevant urban class types such as semi-natural, yet managed land areas that account for differences in ecological functions due to their pervious surfaces may severely constrain assessments. To address this gap, we introduce the managed clearings land-cover type–semi-natural, vegetated land surfaces with varying degrees of management practices–for urbanizing landscapes. We explore the extent to which managed clearings are common and spatially distributed in three rapidly urbanizing areas of the Charlanta megaregion, USA. We visually interpreted and mapped fine-scale land cover with special attention to managed clearings using 2012 U.S. Department of Agriculture (USDA) National Agriculture Imagery Program (NAIP) images within 150 randomly selected 1-km2 blocks in the cities of Atlanta, Charlotte, and Raleigh, and compared our maps with National Land Cover Database (NLCD) data. We estimated the abundance of managed clearings relative to other land use and land cover types, and the proportion of land-cover types in the NLCD that are similar to managed clearings. Our study reveals that managed clearings are the most common land cover type in these cities, covering 28% of the total sampled land area– 6.2% higher than the total area of impervious surfaces. Managed clearings, when combined with forest cover, constitutes 69% of pervious surfaces in the sampled region. We observed variability in area estimates of managed clearings between the NAIP-derived and NLCD data. This suggests using high-resolution remote sensing imagery (e.g., NAIP) instead of modifying NLCD data for improved representation of spatial heterogeneity and

  20. Multidimensional simulation of radon diffusion through earthen covers

    International Nuclear Information System (INIS)

    Mayer, D.W.; Gee, G.W.

    1983-01-01

    The purpose of this report is to document applications of the RADMD model used at PNL to perform analyses of radon diffusion through uranium mill tailings cover systems. The accuracy of the numerical formulation of the RADMD model was demonstrated through a comparison with a two-dimensional analytic solution to the radon diffusion equation. Excellent agreement was obtained between two-dimensional radon concentration profiles predicted by RADMD and those obtained with the analytic solution. A simulation was made of radon diffusion into a test canister using the two dimensional capabilities of RADMD. The radon flux profile was computed and illustrates the effects of the canister on the surface radon flux. The influence of the canister on the radon flux was shown to be significant under certain circumstances. Defects in earthen cover systems were evaluated using the three dimensional capabilities of RADMD. The results support the expectation that defective covers can increase the surface flux from a covered talings pile. Compared to a cover with no defects, radon flux could be elevated by as much as a factor of three when 20% of the radon control layer area contained pockets of reduced moisture. The effects of temporal and spatial variations in moisture content have been modeled by coupling RADMD with a variable saturated flow model. Two dimensional simulations were made of the time dependence of radon flux from a tailings site before and after cover placement. The results demonstrated the expected flux reduction produced by a thick earthen cover. Time dependence of the radon flux after cover placement was attributed to slight changes in moisture content of the cover material with time. The particular cover studied had a compacted clay layer that effectively attenuated the radon

  1. Land Use and Land Cover Change Analysis along the Coastal ...

    African Journals Online (AJOL)

    Agribotix GCS 077

    are carried out on the land usually effect changes in its cover. ... The FAO document on land cover classification systems, (2000) partly answers this ... over the surface land, including water, vegetation, bare soils and or artificial structures. ... diseases may occur more readily in areas exposed by Land Use and Land Cover ...

  2. Engineered soil covers for management of salt impacted sites

    International Nuclear Information System (INIS)

    Sweeney, D.A.; Tratch, D.J.

    2005-01-01

    The use of engineered soil cover systems to mitigate environmental impacts from tailings and waste rock piles is becoming an accepted practice. This paper presented design concepts for soil covers related to reclamation practices in the mining industry as an effective risk management practice at salt impacted sites. Research and field programs have demonstrated that a layered engineered soil cover can reduce or eliminate infiltration. Key components of the system included re-establishing surface vegetation to balance precipitation fluxes with evapotranspiration potential, and design of a capillary break below the rooting zone to minimize deeper seated infiltration. It was anticipated that the incorporation of a vegetation cover and a capillary break would minimize infiltration into the waste rock or tailing pile and reduce the generation of acid rock drainage (ARD). Design of a layered soil cover requires the incorporation of meteorological data, moisture retention characteristics of the impacted soils, and proposed engineered cover materials. Performance of the soil cover was predicted using a finite element model combined with meteorological data from the site area, unsaturated soil properties of the parent sub-surface soils and potential covered materials. The soil cover design consisted of re-vegetation and a loose clay cover overlying a compacted till layer. The design was conducted for an off site release of salt impacted pasture land adjacent to a former highway maintenance yard. The model predicted minimal infiltration during high precipitation events and no infiltration during low precipitation events. Results indicated that the proposed soil cover would enable re-establishment of a productive agricultural ground cover, as well as minimizing the potential for additional salt migration. It was concluded that further research and development is needed to ensure that the cover system is an acceptable method for long-term risk management. 17 refs., 5 figs

  3. STRESSES IN CEMENT-CONCRETE PAVEMENT SURFACING CAUSED BY THERMAL SHOCK

    Directory of Open Access Journals (Sweden)

    M. K. Pshembaev

    2016-01-01

    Full Text Available It is necessary to mention specially so-called thermal shock among various impacts on highway surface. Ice layer is formed on a concrete surface during the winter period of pavement surfacing operation. Sodium chloride which lowers temperature of water-ice transition temperature and causes ice thawing at negative temperature is usually used to remove ice from the pavement surface. Consequently, temperature in the concrete laying immediately under a thawing ice layer is coming down with a run that leads to significant stresses. Such phenomenon is known as a thermal shock with a meaning of local significant change in temperature. This process is under investigation, it has practical importance for an estimation of strength and longevity of a cement-concrete pavement surfacing and consequently it is considered as rather topical issue. The purpose of investigations is to develop a mathematical model and determination of shock blow permissible gradients for a cementconcrete road covering. Finite difference method has been used in order to determine stressed and deformed condition of the cement-concrete pavement surfacing of highways. A computer program has been compiled and it permits to carry out calculation of a road covering at various laws of temperature distribution in its depth. Regularities in distribution of deformation and stresses in the cement-concrete pavement surfacing of highways at thermal shock have been obtained in the paper. A permissible parameter of temperature distribution in pavement surfacing thickness has been determined in the paper. A strength criterion based on the process of micro-crack formation and development in concrete has been used for making calculations. It has been established that the thermal shock causes significant temperature gradients on the cement-concrete surfacing that lead to rather large normal stresses in the concrete surface layer. The possibility of micro-crack formation in a road covering is

  4. Emission of positive oxygen ions from ion bombardment of adsorbate-covered metal surfaces

    International Nuclear Information System (INIS)

    Kaurin, M.G.

    1989-01-01

    During ion bombardment of metal surfaces, collision cascades can result in the emission of sputtered secondary ions. Recent experiments, however, have suggested that the emission of positive ions of electronegative adsorbates can result from electronic processes rather than from processes involving elastic collisions. This dissertation presents the results of experiments studying the emission of positive oxygen ions from oxygen- and carbon-monoxide-covered transition metal surfaces during bombardment by 25-250 keV ions of neon, argon, and krypton. The systems studied may be grouped into four categories. For a nickel substrate with adsorbed oxygen, the emission of positive oxygen ions proceeds through collision cascades. For titanium and niobium with adsorbed oxygen, the emission of positive oxygen ions is proportional to the primary ion velocity, consistent with emission from electronic processes; for a given primary ion velocity, the oxygen ion yield is independent of primary ion species. For substrates of molybdenum and tungsten, the oxygen yield is proportional to primary ion velocity, but the yield also depends on the primary ion species for a given primary ion velocity in a manner that is consistent with emission resulting from electronic processes. For these two groups, except for titanium, the yields during neon ion bombardment do not extrapolate (assuming linearity with primary ion velocity) to a nonzero value at zero beam velocity. The magnitude of the oxygen ion yields from these targets is not consistent with that expected if the emission were induced by secondary electrons emitted during the ion bombardment

  5. Dynamics of forest cover conversion in and around Bwindi ...

    African Journals Online (AJOL)

    Land use/cover map for 2010 was reconstructed by analyzing 2001 image, validated and/or reconstructed by ground truthing, use of secondary data and key ... The severe loss of woodlot outside the protected area not only poses a potential threat to the protected forest but also calls for intervention measures if efforts to ...

  6. Effects of rainfall patterns and land cover on the subsurface flow generation of sloping Ferralsols in southern China.

    Directory of Open Access Journals (Sweden)

    Jian Duan

    Full Text Available Rainfall patterns and land cover are two important factors that affect the runoff generation process. To determine the surface and subsurface flows associated with different rainfall patterns on sloping Ferralsols under different land cover types, observational data related to surface and subsurface flows from 5 m × 15 m plots were collected from 2010 to 2012. The experiment was conducted to assess three land cover types (grass, litter cover and bare land in the Jiangxi Provincial Soil and Water Conservation Ecological Park. During the study period, 114 natural rainfall events produced subsurface flow and were divided into four groups using k-means clustering according to rainfall duration, rainfall depth and maximum 30-min rainfall intensity. The results showed that the total runoff and surface flow values were highest for bare land under all four rainfall patterns and lowest for the covered plots. However, covered plots generated higher subsurface flow values than bare land. Moreover, the surface and subsurface flows associated with the three land cover types differed significantly under different rainfall patterns. Rainfall patterns with low intensities and long durations created more subsurface flow in the grass and litter cover types, whereas rainfall patterns with high intensities and short durations resulted in greater surface flow over bare land. Rainfall pattern I had the highest surface and subsurface flow values for the grass cover and litter cover types. The highest surface flow value and lowest subsurface flow value for bare land occurred under rainfall pattern IV. Rainfall pattern II generated the highest subsurface flow value for bare land. Therefore, grass or litter cover are able to convert more surface flow into subsurface flow under different rainfall patterns. The rainfall patterns studied had greater effects on subsurface flow than on total runoff and surface flow for covered surfaces, as well as a greater effect on surface

  7. Trends in Sea Ice Cover, Sea Surface Temperature, and Chlorophyll Biomass Across a Marine Distributed Biological Observatory in the Pacific Arctic Region

    Science.gov (United States)

    Frey, K. E.; Grebmeier, J. M.; Cooper, L. W.; Wood, C.; Panday, P. K.

    2011-12-01

    The northern Bering and Chukchi Seas in the Pacific Arctic Region (PAR) are among the most productive marine ecosystems in the world and act as important carbon sinks, particularly during May and June when seasonal sea ice-associated phytoplankton blooms occur throughout the region. Recent dramatic shifts in seasonal sea ice cover across the PAR should have profound consequences for this seasonal phytoplankton production as well as the intimately linked higher trophic levels. In order to investigate ecosystem responses to these observed recent shifts in sea ice cover, the development of a prototype Distributed Biological Observatory (DBO) is now underway in the PAR. The DBO is being developed as an internationally-coordinated change detection array that allows for consistent sampling and monitoring at five spatially explicit biologically productive locations across a latitudinal gradient: (1) DBO-SLP (south of St. Lawrence Island (SLI)), (2) DBO-NBS (north of SLI), (3) DBO-SCS (southern Chukchi Sea), (4) DBO-CCS (central Chukchi Sea), and (5) DBO-BCA (Barrow Canyon Arc). Standardized measurements at many of the DBO sites were made by multiple research cruises during the 2010 and 2011 pilot years, and will be expanded with the development of the DBO in coming years. In order to provide longer-term context for the changes occurring across the PAR, we utilize multi-sensor satellite data to investigate recent trends in sea ice cover, chlorophyll biomass, and sea surface temperatures for each of the five DBO sites, as well as a sixth long-term observational site in the Bering Strait. Satellite observations show that over the past three decades, trends in sea ice cover in the PAR have been heterogeneous, with significant declines in the Chukchi Sea, slight declines in the Bering Strait region, but increases in the northern Bering Sea south of SLI. Declines in the persistence of seasonal sea ice cover in the Chukchi Sea and Bering Strait region are due to both earlier sea

  8. Quantification of tillage, plant cover, and cumulative rainfall effects on soil surface microrelief by statistical, geostatistical and fractal indices

    Science.gov (United States)

    Paz-Ferreiro, J.; Bertol, I.; Vidal Vázquez, E.

    2008-07-01

    Changes in soil surface microrelief with cumulative rainfall under different tillage systems and crop cover conditions were investigated in southern Brazil. Surface cover was none (fallow) or the crop succession maize followed by oats. Tillage treatments were: 1) conventional tillage on bare soil (BS), 2) conventional tillage (CT), 3) minimum tillage (MT) and 4) no tillage (NT) under maize and oats. Measurements were taken with a manual relief meter on small rectangular grids of 0.234 and 0.156 m2, throughout growing season of maize and oats, respectively. Each data set consisted of 200 point height readings, the size of the smallest cells being 3×5 cm during maize and 2×5 cm during oats growth periods. Random Roughness (RR), Limiting Difference (LD), Limiting Slope (LS) and two fractal parameters, fractal dimension (D) and crossover length (l) were estimated from the measured microtopographic data sets. Indices describing the vertical component of soil roughness such as RR, LD and l generally decreased with cumulative rain in the BS treatment, left fallow, and in the CT and MT treatments under maize and oats canopy. However, these indices were not substantially affected by cumulative rain in the NT treatment, whose surface was protected with previous crop residues. Roughness decay from initial values was larger in the BS treatment than in CT and MT treatments. Moreover, roughness decay generally tended to be faster under maize than under oats. The RR and LD indices decreased quadratically, while the l index decreased exponentially in the tilled, BS, CT and MT treatments. Crossover length was sensitive to differences in soil roughness conditions allowing a description of microrelief decay due to rainfall in the tilled treatments, although better correlations between cumulative rainfall and the most commonly used indices RR and LD were obtained. At the studied scale, parameters l and D have been found to be useful in interpreting the configuration properties of

  9. Surface structure and morphology of Cu-free and Cu-covered Au(100) and Au(111) electrodes in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Schlaup, Christian [Technical University of Denmark, Department of Physics, Fysikvey, DK-2800 Kongens Lyngby (Denmark); Friebel, Daniel [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, CA 94025 (United States); Wandelt, Klaus [University of Bonn, Institute for Physical und Theoretical Chemistry, Wegelerstr. 12, D-53115 Bonn (Germany)

    2011-07-01

    For both Cu-free Au-electrodes three different phases were observed as a function of the applied electrode potential. While at low potentials the onset of surface reconstruction points towards an apparently adsorbate free surface and, thus, a weak interaction with species from the electrolyte, a Au-hydroxide and a Au-oxide phase are formed subsequently during potential increase. A similar phase behavior was also found for Cu-covered Au-electrodes, while at low potentials an apparently adsorbate free Cu layer is observed, a Cu-hydroxide coadsorbate phase and a Cu-oxide phase are formed under increased potential conditions. In addition the apparently adsorbate free Cu-film tends to form a Cu-Au alloy phase while keeping the electrode for a sufficient long time at low potential conditions.

  10. Electronic states on the clean and oxygen-covered molybdenum (110) surface measured using time-of-flight momentum microscopy

    International Nuclear Information System (INIS)

    Chernov, Sergii

    2016-01-01

    Recent experiments discovered a new class of materials called topological insulators and started an extensive investigation in order to find more materials of such type and to understand and explore the opening perspectives in fundamental science and application. These materials exhibit a Dirac-type (massless) electronic state, bridging the fundamental band gap. Surprisingly, a strongly spin-polarized surface state with linear dispersion resembling that of Dirac type was found on the already well-investigated W(110) surface. This rose the question of the existence of the same non-trivial electron state on other metal surfaces. The present work describes the investigation of surface electronic states on the Mo(110) surface, their dispersion and transformation upon surface oxidation. This system is isoelectronic to the case of W(110) but due to the lower atomic number the spin-orbit interaction responsible for local band gap formation is substantially decreased by a factor of 5. The Mo(110) surface was shown to exhibit a linearly dispersing state quite similar to the one on W(110), but within a smaller energy range of 120 meV, with the Dirac point lying in the center of a local band gap in k-space. The experimental investigations were performed with the help of momentum microscopy, using a Ti:sapphire laser in the lab and synchrotron radiation at BESSY II, Berlin. The results show good agreement with theoretical calculations of the band structure and photoemission patterns for clean Mo(110). The fully parallel 3D acquisition scheme allowed to visualize the full surface Brillouin zone of the sample up to few eV binding energy within a single exposure of typically less than 30 min. This opens the door to future time-resolved experiments with maximum detection efficiency.

  11. Electronic states on the clean and oxygen-covered molybdenum (110) surface measured using time-of-flight momentum microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chernov, Sergii

    2016-04-20

    Recent experiments discovered a new class of materials called topological insulators and started an extensive investigation in order to find more materials of such type and to understand and explore the opening perspectives in fundamental science and application. These materials exhibit a Dirac-type (massless) electronic state, bridging the fundamental band gap. Surprisingly, a strongly spin-polarized surface state with linear dispersion resembling that of Dirac type was found on the already well-investigated W(110) surface. This rose the question of the existence of the same non-trivial electron state on other metal surfaces. The present work describes the investigation of surface electronic states on the Mo(110) surface, their dispersion and transformation upon surface oxidation. This system is isoelectronic to the case of W(110) but due to the lower atomic number the spin-orbit interaction responsible for local band gap formation is substantially decreased by a factor of 5. The Mo(110) surface was shown to exhibit a linearly dispersing state quite similar to the one on W(110), but within a smaller energy range of 120 meV, with the Dirac point lying in the center of a local band gap in k-space. The experimental investigations were performed with the help of momentum microscopy, using a Ti:sapphire laser in the lab and synchrotron radiation at BESSY II, Berlin. The results show good agreement with theoretical calculations of the band structure and photoemission patterns for clean Mo(110). The fully parallel 3D acquisition scheme allowed to visualize the full surface Brillouin zone of the sample up to few eV binding energy within a single exposure of typically less than 30 min. This opens the door to future time-resolved experiments with maximum detection efficiency.

  12. Effects of Nitrogen and Phosphorus Fertilizer and Topsoil Amendment on Native Plant Cover in Roadside Revegetation Projects.

    Science.gov (United States)

    Hillhouse, Heidi L; Schacht, Walter H; Soper, Jonathan M; Wienhold, Carol E

    2018-01-01

    Establishing vegetation on roadsides following construction can be challenging, especially for relatively slow growing native species. Topsoil is generally removed during construction, and the surface soil following construction ("cut-slope soils") is often compacted and low in nutrients, providing poor growing conditions for vegetation. Nebraska Department of Transportation (NDOT) protocols have historically called for nitrogen (N) and phosphorus (P) fertilization when planting roadside vegetation following construction, but these recommendations were developed for cool-season grass plantings and most current plantings use slower-establishing, native warm-season grasses that may benefit less than expected from current planting protocols. We evaluated the effects of nitrogen and phosphorus fertilization, and also topsoil amendment, on the foliar cover of seeded and non-seeded species planted into two post-construction roadside sites in eastern Nebraska. We also examined soil movement to determine how planting protocols and plant growth may affect erosion potential. Three years after planting, we found no consistent effects of N or P fertilization on foliar cover. Plots receiving topsoil amendment had 14% greater cover of warm-season grasses, 10% greater total foliar cover, and 4-13% lower bare ground (depending on site) than plots without topsoil. None of the treatments consistently affected soil movement. We recommend that NDOT change their protocols to remove N and P fertilization and focus on stockpiling and spreading topsoil following construction.

  13. Effects of Nitrogen and Phosphorus Fertilizer and Topsoil Amendment on Native Plant Cover in Roadside Revegetation Projects

    Science.gov (United States)

    Hillhouse, Heidi L.; Schacht, Walter H.; Soper, Jonathan M.; Wienhold, Carol E.

    2018-01-01

    Establishing vegetation on roadsides following construction can be challenging, especially for relatively slow growing native species. Topsoil is generally removed during construction, and the surface soil following construction ("cut-slope soils") is often compacted and low in nutrients, providing poor growing conditions for vegetation. Nebraska Department of Transportation (NDOT) protocols have historically called for nitrogen (N) and phosphorus (P) fertilization when planting roadside vegetation following construction, but these recommendations were developed for cool-season grass plantings and most current plantings use slower-establishing, native warm-season grasses that may benefit less than expected from current planting protocols. We evaluated the effects of nitrogen and phosphorus fertilization, and also topsoil amendment, on the foliar cover of seeded and non-seeded species planted into two post-construction roadside sites in eastern Nebraska. We also examined soil movement to determine how planting protocols and plant growth may affect erosion potential. Three years after planting, we found no consistent effects of N or P fertilization on foliar cover. Plots receiving topsoil amendment had 14% greater cover of warm-season grasses, 10% greater total foliar cover, and 4-13% lower bare ground (depending on site) than plots without topsoil. None of the treatments consistently affected soil movement. We recommend that NDOT change their protocols to remove N and P fertilization and focus on stockpiling and spreading topsoil following construction.

  14. Blended call center with idling times during the call service

    NARCIS (Netherlands)

    Legros, Benjamin; Jouini, Oualid; Koole, Ger

    We consider a blended call center with calls arriving over time and an infinitely backlogged amount of outbound jobs. Inbound calls have a non-preemptive priority over outbound jobs. The inbound call service is characterized by three successive stages where the second one is a break; i.e., there is

  15. Advanced Surface Technology

    DEFF Research Database (Denmark)

    Møller, Per; Nielsen, Lars Pleht

    of the components. It covers everything from biocompatible surfaces of IR absorbent or reflective surfaces to surfaces with specific properties within low friction, hardness, corrosion, colors, etc. The book includes more than 400 pages detailing virtually all analysis methods for examining at surfaces.......This new significant book on advanced modern surface technology in all its variations, is aimed at both teaching at engineering schools and practical application in industry. The work covers all the significant aspects of modern surface technology and also describes how new advanced techniques make...

  16. Scenarios of land cover in China

    Science.gov (United States)

    Yue, Tian Xiang; Fan, Ze Meng; Liu, Ji Yuan

    2007-02-01

    A method for surface modeling of land cover change (SMLC) is developed on the basis of establishing transition probability matrixes between land cover types and HLZ types. SMLC is used to simulate land cover scenarios of China for the years 2039, 2069 and 2099, for which HLZ scenarios are first simulated in terms of HadCM3 climatic scenarios that are downscaled in zonal model of spatial climate change in China. This paper also analyzes spatial distribution of land cover types, area change and mean center shift of each land cover type, ecotope diversity, and patch connectivity under the land cover scenarios. The results show that cultivated land would decrease and woodland would expand greatly with climatic change, which coincides with consequences expected by implementation of Grain-for-Green policy. Nival area would shrink, and desertification area would expand at a comparatively slow rate in future 100 years. Climate change would generally cause less ecotope diversity and more patch connectivity. Ecosystems in China would have a pattern of beneficial cycle after efficient ecological conservation and restoration. However, if human activities would exceed regulation capacity of ecosystems themselves, the ecosystems in China might deteriorate more seriously.

  17. Land cover change mapping using MODIS time series to improve emissions inventories

    Science.gov (United States)

    López-Saldaña, Gerardo; Quaife, Tristan; Clifford, Debbie

    2016-04-01

    MELODIES is an FP7 funded project to develop innovative and sustainable services, based upon Open Data, for users in research, government, industry and the general public in a broad range of societal and environmental benefit areas. Understanding and quantifying land surface changes is necessary for estimating greenhouse gas and ammonia emissions, and for meeting air quality limits and targets. More sophisticated inventories methodologies for at least key emission source are needed due to policy-driven air quality directives. Quantifying land cover changes on an annual basis requires greater spatial and temporal disaggregation of input data. The main aim of this study is to develop a methodology for using Earth Observations (EO) to identify annual land surface changes that will improve emissions inventories from agriculture and land use/land use change and forestry (LULUCF) in the UK. First goal is to find the best sets of input features that describe accurately the surface dynamics. In order to identify annual and inter-annual land surface changes, a times series of surface reflectance was used to capture seasonal variability. Daily surface reflectance images from the Moderate Resolution Imaging Spectroradiometer (MODIS) at 500m resolution were used to invert a Bidirectional Reflectance Distribution Function (BRDF) model to create the seamless time series. Given the limited number of cloud-free observations, a BRDF climatology was used to constrain the model inversion and where no high-scientific quality observations were available at all, as a gap filler. The Land Cover Map 2007 (LC2007) produced by the Centre for Ecology & Hydrology (CEH) was used for training and testing purposes. A land cover product was created for 2003 to 2015 and a bayesian approach was created to identified land cover changes. We will present the results of the time series development and the first exercises when creating the land cover and land cover changes products.

  18. 30 CFR 57.7013 - Covering or guarding drill holes.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Covering or guarding drill holes. 57.7013 Section 57.7013 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... and Rotary Jet Piercing Drilling-Surface Only § 57.7013 Covering or guarding drill holes. Drill holes...

  19. Special study on vegetative covers

    International Nuclear Information System (INIS)

    1988-11-01

    This report describes the findings of a special study on the use of vegetative covers to stabilize tailings piles for the Uranium Mill Tailings Remedial Action (UMTRA) Project. The principal rationale for using plants would be to establish a dynamic system for controlling water balance. Specifically, vegetation would be used to intercept and transpire precipitation to the atmosphere, rather than allowing water to drain into the tailings and mobilize contaminants. This would facilitate compliance with groundwater standards proposed for the UMTRA Project by the Environmental Protection Agency. The goals of the study were to evaluate the feasibility of using vegetative covers on UMTRA Project piles, define the advantages and disadvantages of vegetative covers, and develop general guidelines for their use when such use seems reasonable. The principal method for the study was to analyze and apply to the UMTRA Project the results of research programs on vegetative covers at other US Department of Energy (DOE) waste management facilities. The study also relied upon observations made of existing stabilized piles at UMTRA Project sites where natural vegetation is growing on the rock-covered surfaces. Water balance and erosion models were also used to quantify the long-term performance of vegetative covers planned for the topslopes of stabilized piles at Grand Junction and Durango, Colorado, two UMTRA Project sites where the decision was made during the course of this special study to use vegetative covers. Elements in the design and construction of the vegetative covers at these two sites are discussed in the report, with explanations of the differing features that reflect differing environmental conditions. 28 refs., 18 figs., 9 tabs

  20. Do cover crop mixtures have the same ability to suppress weeds as competitive monoculture cover crops?

    Directory of Open Access Journals (Sweden)

    Brust, Jochen

    2014-02-01

    Full Text Available An increasing number of farmers use cover crop mixtures instead of monoculture cover crops to improve soil and crop quality. However, only little information is available about the weed suppression ability of cover crop mixtures. Therefore, two field experiments were conducted in Baden-Württemberg between 2010 and 2012, to compare growth and weed suppression of monoculture cover crops and cover crop mixtures. In the first experiment, heterogeneous results between yellow mustard and the cover crop mixture occurred. For further research, a field experiment was conducted in 2012 to compare monocultures of yellow mustard and hemp with three cover crop mixtures. The evaluated mixtures were: “MELO”: for soil melioration; “BETA”: includes only plant species with no close relation to main cash crops in Central Europe and “GPS”: for usage as energy substrate in spring. Yellow mustard, MELO, BETA and GPS covered 90% of the soil in less than 42 days and were able to reduce photosynthetically active radiation (PAR on soil surface by more than 96% after 52 days. Hemp covered 90% of the soil after 47 days and reduced PAR by 91% after 52 days. Eight weeks after planting, only BETA showed similar growth to yellow mustard which produced the highest dry matter. The GPS mixture had comparatively poor growth, while MELO produced similar dry matter to hemp. Yellow mustard, MELO and BETA reduced weed growth by 96% compared with a no cover crop control, while hemp and GPS reduced weeds by 85% and 79%. In spring, weed dry matter was reduced by more than 94% in plots with yellow mustard and all mixtures, while in hemp plots weeds were only reduced by 71%. The results suggest that the tested cover crop mixtures offer similar weed suppression ability until spring as the monoculture of the competitive yellow mustard.

  1. Potential solar radiation and land cover contributions to digital climate surface modeling

    Science.gov (United States)

    Puig, Pol; Batalla, Meritxell; Pesquer, Lluís; Ninyerola, Miquel

    2016-04-01

    Overview: We have designed a series of ad-hoc experiments to study the role of factors that a priori have a strong weight in developing digital models of temperature and precipitation, such as solar radiation and land cover. Empirical test beds have been designed to improve climate (mean air temperature and total precipitation) digital models using statistical general techniques (multiple regression) with residual correction (interpolated with inverse weighting distance). Aim: Understand what roles these two factors (solar radiation and land cover) play to incorporate them into the process of generating mapping of temperature and rainfall. Study area: The Iberian Peninsula and supported in this, Catalonia and the Catalan Pyrenees. Data: The dependent variables used in all experiments relate to data from meteorological stations precipitation (PL), mean temperature (MT), average temperature minimum (MN) and maximum average temperature (MX). These data were obtained monthly from the AEMET (Agencia Estatal de Meteorología). Data series of stations covers the period between 1950 to 2010. Methodology: The idea is to design ad hoc, based on a sample of more equitable space statistician, to detect the role of radiation. Based on the influence of solar radiation on the temperature of the air from a quantitative point of view, the difficulty in answering this lies in the fact that there are lots of weather stations located in areas where solar radiation is similar. This suggests that the role of the radiation variable remains "off" when, instead, we intuitively think that would strongly influence the temperature. We have developed a multiple regression analysis between these meteorological variables as the dependent ones (Temperature and rainfall), and some geographical variables: altitude (ALT), latitude (LAT), continentality (CON) and solar radiation (RAD) as the independent ones. In case of the experiment with land covers, we have used the NDVI index as a proxy of land

  2. Efficiency of a concentric matrix track detector surface scanning

    International Nuclear Information System (INIS)

    Bek-Uzarov, Dj.; Nikezic, D.; Kostic, D.; Krstic, D.; Cuknic, O.

    1995-01-01

    Heavy particle ionizing radiation track counting on the surface of a solid state round surface detector is made using the microscope and scanning step by step by a round field of vision. The whole solid state detector surface could not be fully or completely covered by round fields of visions. Therefore detector surface could be divided on the two parts, the larger surface, being under fields of vision, really scanned and no scanned missed or omitted surface. The ratio between omitted and scanned surfaces is so called track scanning efficiency. The knowledge of really counted, or scanned surface is a important value for evaluating the real surface track density an exposed solid state track detector. In the paper a matrix of a concentric field of vision made around the first microscope field of vision placed in center of the round disc of the scanned track detector is proposed. In a such scanning matrix the real scanned surface could be easy calculated and by the microscope scanning made as well. By this way scanned surface is very precisely obtained as well. Precise knowledge of scanned and omitted surface allows to obtain more precise scanning efficiency factor as well as real surface track density, the main parameter in solid state track detection measurements. (author)

  3. Integrated Landsat Image Analysis and Hydrologic Modeling to Detect Impacts of 25-Year Land-Cover Change on Surface Runoff in a Philippine Watershed

    Directory of Open Access Journals (Sweden)

    Enrico Paringit

    2011-05-01

    Full Text Available Landsat MSS and ETM+ images were analyzed to detect 25-year land-cover change (1976–2001 in the critical Taguibo Watershed in Mindanao Island, Southern Philippines. This watershed has experienced historical modifications of its land-cover due to the presence of logging industries in the 1950s, and continuous deforestation due to illegal logging and slash-and-burn agriculture in the present time. To estimate the impacts of land-cover change on watershed runoff, land-cover information derived from the Landsat images was utilized to parameterize a GIS-based hydrologic model. The model was then calibrated with field-measured discharge data and used to simulate the responses of the watershed in its year 2001 and year 1976 land-cover conditions. The availability of land-cover information on the most recent state of the watershed from the Landsat ETM+ image made it possible to locate areas for rehabilitation such as barren and logged-over areas. We then created a “rehabilitated” land-cover condition map of the watershed (re-forestation of logged-over areas and agro-forestation of barren areas and used it to parameterize the model and predict the runoff responses of the watershed. Model results showed that changes in land-cover from 1976 to 2001 were directly related to the significant increase in surface runoff. Runoff predictions showed that a full rehabilitation of the watershed, especially in barren and logged-over areas, will be likely to reduce the generation of a huge volume of runoff during rainfall events. The results of this study have demonstrated the usefulness of multi-temporal Landsat images in detecting land-cover change, in identifying areas for rehabilitation, and in evaluating rehabilitation strategies for management of tropical watersheds through its use in hydrologic modeling.

  4. Harder–Narasimhan filtration for rank 2 tensors and stable coverings

    Indian Academy of Sciences (India)

    We call σ the Harder–Narasimhan section of the covering. Acknowledgements. The author wishes to thank Usha Bhosle, Tomás L Gómez and Peter Newstead for useful discussions, and to the Isaac Newton Institute for Mathematical Sciences in Cambridge,. United Kingdom, where part of this work was done, for hospitality.

  5. Estimating Snow Cover from Publicly Available Images

    OpenAIRE

    Fedorov, Roman; Camerada, Alessandro; Fraternali, Piero; Tagliasacchi, Marco

    2016-01-01

    In this paper we study the problem of estimating snow cover in mountainous regions, that is, the spatial extent of the earth surface covered by snow. We argue that publicly available visual content, in the form of user generated photographs and image feeds from outdoor webcams, can both be leveraged as additional measurement sources, complementing existing ground, satellite and airborne sensor data. To this end, we describe two content acquisition and processing pipelines that are tailored to...

  6. Cover Crop (Rye) and No-Till System in Wisconsin

    OpenAIRE

    Alföldi, Thomas

    2014-01-01

    Erin Silva, University of Wisconsin, describes an organic no-till production technique using rye as cover crop to suppress weeds in the following production season. Using a roller-crimper, the overwintering rye is terminated at the time of cash crop planting, leaving a thick mat of plant residue on the soil surface. Soybeans are sown directly into the cover crop residue, allowing the cash crop to emerge through the terminated cover crop while suppressing weeds throughout the season. W...

  7. Modeled impact of anthropogenic land cover change on climate

    Science.gov (United States)

    Findell, K.L.; Shevliakova, E.; Milly, P.C.D.; Stouffer, R.J.

    2007-01-01

    Equilibrium experiments with the Geophysical Fluid Dynamics Laboratory's climate model are used to investigate the impact of anthropogenic land cover change on climate. Regions of altered land cover include large portions of Europe, India, eastern China, and the eastern United States. Smaller areas of change are present in various tropical regions. This study focuses on the impacts of biophysical changes associated with the land cover change (albedo, root and stomatal properties, roughness length), which is almost exclusively a conversion from forest to grassland in the model; the effects of irrigation or other water management practices and the effects of atmospheric carbon dioxide changes associated with land cover conversion are not included in these experiments. The model suggests that observed land cover changes have little or no impact on globally averaged climatic variables (e.g., 2-m air temperature is 0.008 K warmer in a simulation with 1990 land cover compared to a simulation with potential natural vegetation cover). Differences in the annual mean climatic fields analyzed did not exhibit global field significance. Within some of the regions of land cover change, however, there are relatively large changes of many surface climatic variables. These changes are highly significant locally in the annual mean and in most months of the year in eastern Europe and northern India. They can be explained mainly as direct and indirect consequences of model-prescribed increases in surface albedo, decreases in rooting depth, and changes of stomatal control that accompany deforestation. ?? 2007 American Meteorological Society.

  8. Extractable Bacterial Surface Proteins in Probiotic–Host Interaction

    Directory of Open Access Journals (Sweden)

    Fillipe L. R. do Carmo

    2018-04-01

    Full Text Available Some Gram-positive bacteria, including probiotic ones, are covered with an external proteinaceous layer called a surface-layer. Described as a paracrystalline layer and formed by the self-assembly of a surface-layer-protein (Slp, this optional structure is peculiar. The surface layer per se is conserved and encountered in many prokaryotes. However, the sequence of the corresponding Slp protein is highly variable among bacterial species, or even among strains of the same species. Other proteins, including surface layer associated proteins (SLAPs, and other non-covalently surface-bound proteins may also be extracted with this surface structure. They can be involved a various functions. In probiotic Gram-positives, they were shown by different authors and experimental approaches to play a role in key interactions with the host. Depending on the species, and sometime on the strain, they can be involved in stress tolerance, in survival within the host digestive tract, in adhesion to host cells or mucus, or in the modulation of intestinal inflammation. Future trends include the valorization of their properties in the formation of nanoparticles, coating and encapsulation, and in the development of new vaccines.

  9. Recent land cover history and nutrient retention in riparian wetlands

    Science.gov (United States)

    Hogan, D.M.; Walbridge, M.R.

    2009-01-01

    Wetland ecosystems are profoundly affected by altered nutrient and sediment loads received from anthropogenic activity in their surrounding watersheds. Our objective was to compare a gradient of agricultural and urban land cover history during the period from 1949 to 1997, with plant and soil nutrient concentrations in, and sediment deposition to, riparian wetlands in a rapidly urbanizing landscape. We observed that recent agricultural land cover was associated with increases in Nitrogen (N) and Phosphorus (P) concentrations in a native wetland plant species. Conversely, recent urban land cover appeared to alter receiving wetland environmental conditions by increasing the relative availability of P versus N, as reflected in an invasive, but not a native, plant species. In addition, increases in surface soil Fe content suggests recent inputs of terrestrial sediments associated specifically with increasing urban land cover. The observed correlation between urban land cover and riparian wetland plant tissue and surface soil nutrient concentrations and sediment deposition, suggest that urbanization specifically enhances the suitability of riparian wetland habitats for the invasive species Japanese stiltgrass [Microstegium vimenium (Trinius) A. Camus]. ?? 2009 Springer Science+Business Media, LLC.

  10. Interrelationship between cloud cover and sensible heat flux over ...

    Indian Academy of Sciences (India)

    Micro-meteorological tower observations of MONTBLEX (Monsoon Trough Boundary Layer Experiment)-1990, combined with routine surface observations at Jodhpur in the dry convective sector of Indian summer monsoon trough are used to examine the interrelationship between total cloud cover (TCC) and surface ...

  11. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    KAUST Repository

    Jadoon, Khan

    2015-09-18

    We tested an off-ground ground-penetrating radar (GPR) system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  12. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    KAUST Repository

    Jadoon, Khan; Weihermller, Lutz; McCabe, Matthew; Moghadas, Davood; Vereecken, Harry; Lambot, Sbastien

    2015-01-01

    We tested an off-ground ground-penetrating radar (GPR) system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  13. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Khan Zaib Jadoon

    2015-09-01

    Full Text Available We tested an off-ground ground-penetrating radar (GPR system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  14. Estimation of runoff mitigation by morphologically different cover crop root systems

    Science.gov (United States)

    Yu, Yang; Loiskandl, Willibald; Kaul, Hans-Peter; Himmelbauer, Margarita; Wei, Wei; Chen, Liding; Bodner, Gernot

    2016-07-01

    Hydrology is a major driver of biogeochemical processes underlying the distinct productivity of different biomes, including agricultural plantations. Understanding factors governing water fluxes in soil is therefore a key target for hydrological management. Our aim was to investigate changes in soil hydraulic conductivity driven by morphologically different root systems of cover crops and their impact on surface runoff. Root systems of twelve cover crop species were characterized and the corresponding hydraulic conductivity was measured by tension infiltrometry. Relations of root traits to Gardner's hydraulic conductivity function were determined and the impact on surface runoff was estimated using HYDRUS 2D. The species differed in both rooting density and root axes thickness, with legumes distinguished by coarser axes. Soil hydraulic conductivity was changed particularly in the plant row where roots are concentrated. Specific root length and median root radius were the best predictors for hydraulic conductivity changes. For an intensive rainfall simulation scenario up to 17% less rainfall was lost by surface runoff in case of the coarsely rooted legumes Melilotus officinalis and Lathyrus sativus, and the densely rooted Linum usitatissimum. Cover crops with coarse root axes and high rooting density enhance soil hydraulic conductivity and effectively reduce surface runoff. An appropriate functional root description can contribute to targeted cover crop selection for efficient runoff mitigation.

  15. Multiple trigger scintillators were installed: big ones covering the total surface of the sensor and several smaller ones. The former give a trigger for each beam particle. The latter are used to select a part of the sensor surface for efficiency measurements.

    CERN Multimedia

    Nooren, G.

    2004-01-01

    Multiple trigger scintillators were installed: big ones covering the total surface of the sensor and several smaller ones. The former give a trigger for each beam particle. The latter are used to select a part of the sensor surface for efficiency measurements.

  16. Summary of decontamination cover manufacturing experience

    International Nuclear Information System (INIS)

    Ulrich, G.B.; Berry, H.W.

    1995-02-01

    Decontamination cover forming cracks and vent cup assembly leaks through the decontamination covers were early manufacturing problems. The decontamination cover total manufacturing process yield was as low as 55%. Applicable tooling and procedures were examined. All manufacturing steps from foil fabrication to final assembly leak testing were considered as possible causes or contributing factors to these problems. The following principal changes were made to correct these problems: (1) the foil annealing temperature was reduced from 1375 degrees to 1250 degrees C, (2) the decontamination cover fabrication procedure (including visual inspection for surface imperfections and elimination of superfluous operations) was improved, (3) the postforming dye penetrant inspection procedure was revised for increased sensitivity, (4) a postforming (prewelding) 1250 degrees C/1 h vacuum stress-relief operation was added, (5) a poststress relief (prewelding) decontamination cover piece-part leak test was implemented, (6) the hold-down fixture used during the decontamination cover-to-cup weld was modified, and concomitantly, and (7) the foil fabrication process was changed from the extruding and rolling of 63-mm-diam vacuum arc-remelted ingots (extrusion process) to the rolling of 19-mm-square arc-melted drop castings (drop cast process). Since these changes were incorporated, the decontamination cover total manufacturing process yield has been 91 %. Most importantly, more than 99% of the decontamination covers welded onto vent cup assemblies were acceptable. The drastic yield improvement is attributed primarily to the change in the foil annealing temperature from 1375 degrees to 1250 degrees C and secondarily to the improvements in the decontamination cover fabrication procedure

  17. Impacts of land use/cover classification accuracy on regional climate simulations

    Science.gov (United States)

    Ge, Jianjun; Qi, Jiaguo; Lofgren, Brent M.; Moore, Nathan; Torbick, Nathan; Olson, Jennifer M.

    2007-03-01

    Land use/cover change has been recognized as a key component in global change. Various land cover data sets, including historically reconstructed, recently observed, and future projected, have been used in numerous climate modeling studies at regional to global scales. However, little attention has been paid to the effect of land cover classification accuracy on climate simulations, though accuracy assessment has become a routine procedure in land cover production community. In this study, we analyzed the behavior of simulated precipitation in the Regional Atmospheric Modeling System (RAMS) over a range of simulated classification accuracies over a 3 month period. This study found that land cover accuracy under 80% had a strong effect on precipitation especially when the land surface had a greater control of the atmosphere. This effect became stronger as the accuracy decreased. As shown in three follow-on experiments, the effect was further influenced by model parameterizations such as convection schemes and interior nudging, which can mitigate the strength of surface boundary forcings. In reality, land cover accuracy rarely obtains the commonly recommended 85% target. Its effect on climate simulations should therefore be considered, especially when historically reconstructed and future projected land covers are employed.

  18. A Binary Cat Swarm Optimization Algorithm for the Non-Unicost Set Covering Problem

    Directory of Open Access Journals (Sweden)

    Broderick Crawford

    2015-01-01

    Full Text Available The Set Covering Problem consists in finding a subset of columns in a zero-one matrix such that they cover all the rows of the matrix at a minimum cost. To solve the Set Covering Problem we use a metaheuristic called Binary Cat Swarm Optimization. This metaheuristic is a recent swarm metaheuristic technique based on the cat behavior. Domestic cats show the ability to hunt and are curious about moving objects. Based on this, the cats have two modes of behavior: seeking mode and tracing mode. We are the first ones to use this metaheuristic to solve this problem; our algorithm solves a set of 65 Set Covering Problem instances from OR-Library.

  19. Bacteria at glacier surfaces: microbial community structures in debris covered glaciers and cryoconites in the Italian Alps

    Science.gov (United States)

    Azzoni, Roberto; Franzetti, Andrea; Ambrosini, Roberto; D'Agata, Carlo; Senese, Antonella; Minora, Umberto; Tagliaferri, Ilario; Diolaiuti, Guglielmina

    2014-05-01

    Supraglacial debris has an important role in the glacier energy budget and has strong influence on the glacial ecosystem. Sediment derives generally from rock inputs from nesting rockwalls and are abundant and continuous at the surface of debris-covered glaciers (i.e. DCGs; glaciers where the ablation area is mainly covered by rock debris) and sparse and fine on debris-free glaciers (DFGs). Recently, evidence for significant tongue darkening on retreating debris-free glaciers has been drawing increasing attention. Fine particles, the cryoconite, are locally abundant and may form cryoconite holes that are water-filled depressions on the surface of DFGs that form when a thin layer of cryoconite is heated by the sun and melts the underlying ice. There is increasing evidence that cryoconite holes also host highly diverse microbial communities and can significantly contribute to global carbon cycle. However, there is almost no study on microbial communities of the debris cover of DCGs and there is a lack of data from the temporal evolution of the microbial communities in the cryoconites. To fill these gaps in our knowledge we characterized the supraglacial debris of two Italian DCGs and we investigated the temporal evolution of microbial communities on cryoconite holes in DFG. We used the Illumina technology to analyse the V5 and V6 hypervariable regions of the bacterial 16S rRNA gene amplified from samples collected distances from the terminus of two DCGs (Miage and Belvedere Glaciers - Western Italian Alps). Heterotrophic taxa dominated bacterial communities, whose structure changed during downwards debris transport. Organic carbon of these recently exposed substrates therefore is probably provided more by allochthonous deposition of organic matter than by primary production by autotrophic organisms. We used ARISA fingerprinting and quantitative PCR to describe the structure and the evolution of the microbial communities and to estimate the number of the total

  20. Low-temperature gaseous surface hardening of stainless steel: the current status

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2009-01-01

    a hardened case at the surface, while maintaining the superior corrosion performance. This can be achieved by dissolving colossal amounts of nitrogen and/or carbon without forming nitrides and/or carbides, thus developing so-called expanded austenite. The present work gives an overview over results obtained...... on homogeneous expanded austenite and covers the crystallography for nitrogen- and carbon-stabilised expanded austenite, the solubility for nitrogen and carbon, the diffusion of these interstitials as well as the stability of expanded austenite with respect to nitride and carbide formation. Subsequently...

  1. The Thermal Collector With Varied Glass Covers

    International Nuclear Information System (INIS)

    Luminosu, I.; Pop, N.

    2010-01-01

    The thermal collector with varied glass covers represents an innovation realized in order to build a collector able to reach the desired temperature by collecting the solar radiation from the smallest surface, with the highest efficiency. In the case of the thermal collector with variable cover glasses, the number of the glass plates covering the absorber increases together with the length of the circulation pipe for the working fluid. The thermal collector with varied glass covers compared to the conventional collector better meet user requirements because: for the same temperature increase, has the collecting area smaller; for the same collection area, realizes the highest temperature increase and has the highest efficiency. This works is addressed to researchers in the solar energy and to engineers responsible with air-conditioning systems design or industrial and agricultural products drying.

  2. Dynamic call center routing policies using call waiting and agent idle times

    NARCIS (Netherlands)

    Chan, W.; Koole, G.M.; L'Ecuyer, P.

    2014-01-01

    We study call routing policies for call centers with multiple call types and multiple agent groups. We introduce new weight-based routing policies where each pair (call type, agent group) is given a matching priority defined as an affine combination of the longest waiting time for that call type and

  3. Process and associated equipment for decontaminating, cleaning all surfaces which are covered with transferrable contamination of a nuclear nature, without creating other wastes

    International Nuclear Information System (INIS)

    Tiesse, J.-C.G.; Chauvet, S.; Chabert, R.E.; Dezu, M.D.

    1989-01-01

    The invention relates to a process for removing all transferrable contamination of a nuclear nature without creating new nuclear contamination wastes. This process is characterised by the following three stages: spraying and covering the contaminated surfaces with dry ice, without causing any blast; spraying a jet of steam or hot air on to the coated surfaces from very close range; forced ventilation causing total evaporation of the dry ice, bringing about the phenomenon of sublimation. The device for applying the process comprises a dry ice emitter and a spray nozzle for water vapour at a temperature in excess of 70 0 C. (author)

  4. Hydrological Modelling and data assimilation of Satellite Snow Cover Area using a Land Surface Model, VIC

    Directory of Open Access Journals (Sweden)

    S. Naha

    2016-06-01

    Full Text Available The snow cover plays an important role in Himalayan region as it contributes a useful amount to the river discharge. So, besides estimating rainfall runoff, proper assessment of snowmelt runoff for efficient management and water resources planning is also required. A Land Surface Model, VIC (Variable Infiltration Capacity is used at a high resolution grid size of 1 km. Beas river basin up to Thalot in North West Himalayas (NWH have been selected as the study area. At first model setup is done and VIC has been run in its energy balance mode. The fluxes obtained from VIC has been routed to simulate the discharge for the time period of (2003-2006. Data Assimilation is done for the year 2006 and the techniques of Data Assimilation considered in this study are Direct Insertion (D.I and Ensemble Kalman Filter (EnKF that uses observations of snow covered area (SCA to update hydrologic model states. The meteorological forcings were taken from 0.5 deg. resolution VIC global forcing data from 1979-2006 with daily maximum temperature, minimum temperature from Climate Research unit (CRU, rainfall from daily variability of NCEP and wind speed from NCEP-NCAR analysis as main inputs and Indian Meteorological Department (IMD data of 0.25 °. NBSSLUP soil map and land use land cover map of ISRO-GBP project for year 2014 were used for generating the soil parameters and vegetation parameters respectively. The threshold temperature i.e. the minimum rain temperature is -0.5°C and maximum snow temperature is about +0.5°C at which VIC can generate snow fluxes. Hydrological simulations were done using both NCEP and IMD based meteorological Forcing datasets, but very few snow fluxes were obtained using IMD data met forcing, whereas NCEP based met forcing has given significantly better snow fluxes throughout the simulation years as the temperature resolution as given by IMD data is 0.5°C and rainfall resolution of 0.25°C. The simulated discharge has been validated

  5. Impacts of land use and cover change on terrestrial carbon stocks and the micro-climate over urban surface: a case study in Shanghai, China

    Science.gov (United States)

    Zhang, F.; Zhan, J.; Bai, Y.

    2016-12-01

    Land use and cover change is the key factor affecting terrestrial carbon stocks and micro-climate, and their dynamics not only in regional ecosystems but also in urbanized areas. Using the typical fast-growing city of Shanghai, China as a case study, this paper explored the relationships between terrestrial carbon stocks, micro-climate and land cover within an urbanized area. The main objectives were to assess variation in soil carbon stocks and local climate conditions across terrestrial land covers with different intensities of urban development, and quantify spatial distribution and dynamic variation of carbon stocks and microclimate in response to urban land use and cover change. On the basis of accurate spatial datasets derived from a series of Landsat TM images during the years 1988 to 2010 and reliable estimates of urban climate and soil carbon stocks using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, our results showed that carbon stocks per unit area in terrestrial land covers decreased and urban temperature increased with increasing intensity of urban development. Urban land use and cover change and sealing of the soil surface created hotspots for losses in carbon stocks. Total carbon stocks in Shanghai decreased by about 30%-35%, representing a 1.5% average annual decrease, and the temperature increased by about 0.23-0.4°/10a during the past 20 years. We suggested potential policy measures to mitigate negative effects of land use and cover change on carbon stocks and microclimate in urbanized areas.

  6. Frozen soil and snow cover with respect to the hydrological land-surface behaviour; Gefrorener Boden und Schneebedeckung unter besonderer Beruecksichtigung des hydrologischen Verhaltens der Landoberflaeche

    Energy Technology Data Exchange (ETDEWEB)

    Warrach, K. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    2000-07-01

    Investigations of the water and energy cycle in the climate system using atmospheric circulation models require a proper representation of the land surface. The land-surface model SEWAB calculates the vertical exchange of water and energy between the atmosphere and the land-surface. This includes the calculation of runoff from the land-surface into the rivers and of the vertical heat and water fluxes within the soil. The inclusion of soil freezing and thawing and the accumulation and ablation of a snow cover in SEWAB is introduced. Additionally changes in the runoff calculation such as the inclusion of the TOPMODEL-approach to consider orographic effects are made. Applications carried out for various regions of North America show good agreement between model results and measurements. (orig.)

  7. Sky cover from MFRSR observations

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-07-01

    Full Text Available The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their modeled clear-sky counterparts are the main components of a new method for estimating the fractional sky cover of different cloud types, including cumuli. The performance of this method is illustrated using 1-min resolution data from a ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR. The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM Climate Research Facility (ACRF Southern Great Plains (SGP site during the summer of 2007 and represent 13 days with cumuli. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

  8. Surface for dummies

    CERN Document Server

    Rathbone, Andy

    2014-01-01

    Make Microsoft's Surface work-and play-just the way you want it to Microsoft's Surface tablet has the features and personality you're looking for, with a robust environment for business computing that doesn't skimp on fun. Surface for Dummies, 2nd Edition explains how Windows 8.1 Pro and Windows RT differ, and helps you decide which Surface model is best for you. Step by step, this book walks you through both the hardware and software features of the Surface, including the touch cover and type cover, Windows RT and Windows 8.1 Pro operating systems, and the coveted Office Home & Student 2013 s

  9. Rangeland monitoring using remote sensing: comparison of cover estimates from field measurements and image analysis

    Directory of Open Access Journals (Sweden)

    Ammon Boswell

    2017-01-01

    Full Text Available Rangeland monitoring is important for evaluating and assessing semi-arid plant communities. Remote sensing provides an effective tool for rapidly and accurately assessing rangeland vegetation and other surface attributes such as bare soil and rock. The purpose of this study was to evaluate the efficacy of remote sensing as a surrogate for field-based sampling techniques in detecting ground cover features (i.e., trees, shrubs, herbaceous cover, litter, surface, and comparing results with field-based measurements collected by the Utah Division of Wildlife Resources Range Trent Program. In the field, five 152 m long transects were used to sample plant, litter, rock, and bare-ground cover using the Daubenmire ocular estimate method. At the same location of each field plot, a 4-band (R,G,B,NIR, 25 cm pixel resolution, remotely sensed image was taken from a fixed-wing aircraft. Each image was spectrally classified producing 4 cover classes (tree, shrub, herbaceous, surface. No significant differences were detected between canopy cover collected remotely and in the field for tree (P = 0.652, shrub (P = 0.800, and herbaceous vegetation (P = 0.258. Surface cover was higher in field plots (P < 0.001, likely in response to the methods used to sample surface features by field crews. Accurately classifying vegetation and other features from remote sensed information can improve the efficiency of collecting vegetation and surface data. This information can also be used to improve data collection frequency for rangeland monitoring and to efficiently quantify ecological succession patterns.

  10. Physics Letters B, Volume 716, Issue 1- Cover Page

    CERN Multimedia

    CERN

    2012-01-01

    The cover page of the Physics Letters B Journal, Volume 716, Issue 1, dedicated to the observation of a new particle in the search for the Standard Model Higgs boson. To celebrate this historical discovery, Elsevier reprinted the ATLAS and the CMS articles together with a foreword by Peter Higgs and the other scientists that predicted the existence of the so-called Higgs boson and published this in a separate booklet.

  11. Aryl diazonium salts: a new class of coupling agents for bonding polymers, biomacromolecules and nanoparticles to surfaces.

    Science.gov (United States)

    Mahouche-Chergui, Samia; Gam-Derouich, Sarra; Mangeney, Claire; Chehimi, Mohamed M

    2011-07-01

    This critical review summarizes existing knowledge on the use of diazonium salts as a new generation of surface modifiers and coupling agents for binding synthetic polymers, biomacromolecules, and nanoparticles to surfaces. Polymer grafts can be directly grown at surfaces through the so-called grafting from approaches based on several polymerization methods but can also be pre-formed in solution and then grafted to surfaces through grafting onto strategies including "click" reactions. Several routes are also described for binding biomacromolecules through aryl layers in view of developing biosensors and protein arrays, while the use of aryl diazonium coupling agents is extended to the attachment of nanoparticles. Patents and industrial applications of the surface chemistry of diazonium compounds are covered. This review stresses the paramount role of aryl diazonium coupling agents in adhesion, surface and materials sciences (114 references).

  12. Albedo of the ice covered Weddell and Bellingshausen Seas

    OpenAIRE

    A. I. Weiss; J. C. King; T. A. Lachlan-Cope; R. S. Ladkin

    2012-01-01

    This study investigates the surface albedo of the sea ice areas adjacent to the Antarctic Peninsula during the austral summer. Aircraft measurements of the surface albedo, which were conducted in the sea ice areas of the Weddell and Bellingshausen Seas show significant differences between these two regions. The averaged surface albedo varied between 0.13 and 0.81. The ice cover of the Bellingshausen Sea consisted mainly of first year ice and the sea surface showed an averaged sea ice albedo o...

  13. Albedo of the ice-covered Weddell and Bellingshausen Sea

    OpenAIRE

    A. I. Weiss; J. C. King; T. A. Lachlan-Cope; R. S. Ladkin

    2011-01-01

    This study investigates the surface albedo of the sea ice areas adjacent to the Antarctic Peninsula during the austral summer. Aircraft measurements of the surface albedo which were conducted in the sea ice areas of the Weddell and Bellingshausen Sea show significant differences between these two regions. The averaged surface albedo varied between 0.13 and 0.81. The ice cover of the Bellingshausen Sea consisted mainly of first year ice and the sea surface showed an averaged sea ice albed...

  14. Car Covers | Outdoor Covers Canada

    OpenAIRE

    Covers, Outdoor

    2018-01-01

    Protect your car from the elements with Ultimate Touch Car Cover. The multi-layer non-woven fabric is soft on the finish and offers 4 seasons all weather protection.https://outdoorcovers.ca/car-covers/

  15. 47 CFR 22.921 - 911 call processing procedures; 911-only calling mode.

    Science.gov (United States)

    2010-10-01

    ... programming in the mobile unit that determines the handling of a non-911 call and permit the call to be... CARRIER SERVICES PUBLIC MOBILE SERVICES Cellular Radiotelephone Service § 22.921 911 call processing procedures; 911-only calling mode. Mobile telephones manufactured after February 13, 2000 that are capable of...

  16. Vibro-Acoustic Numerical Analysis for the Chain Cover of a Car Engine

    Directory of Open Access Journals (Sweden)

    Enrico Armentani

    2017-06-01

    Full Text Available In this work, a vibro-acoustic numerical and experimental analysis was carried out for the chain cover of a low powered four-cylinder four-stroke diesel engine, belonging to the FPT (FCA Power Train family called SDE (Small Diesel Engine. By applying a methodology used in the acoustic optimization of new FPT engine components, firstly a finite element model (FEM of the engine was defined, then a vibration analysis was performed for the whole engine (modal analysis, and finally a forced response analysis was developed for the only chain cover (separated from the overall engine. The boundary conditions applied to the chain cover were the accelerations experimentally measured by accelerometers located at the points of connection among chain cover, head cover, and crankcase. Subsequently, a boundary element (BE model of the only chain cover was realized to determine the chain cover noise emission, starting from the previously calculated structural vibrations. The numerical vibro-acoustic outcomes were compared with those experimentally observed, obtaining a good correlation. All the information thus obtained allowed the identification of those critical areas, in terms of noise generation, in which to undertake necessary improvements.

  17. Plastic-covered agriculture forces the regional climate to change

    Science.gov (United States)

    Yang, D.; Chen, J.; Chen, X.; Cao, X.

    2016-12-01

    The practice of plastic-covered agriculture as a solution to moderate the dilemma of global food shortage, meanwhile, brings great pressure to the local environment. This research was conducted to reveal the impacts of plastic-covered agritulture on regional climate change by experimenting in a plastic greenhouse (PG) dominated area - Weifang district, Shandong province, China. Based on a new plastic greenhouse index (PGI) proposed in this study, we reconstructed the spatial distribution of PG across 1995-2015 in the study area. With that, land surface temperature (LST) dataset combined with surface evapotranspiration, surface reflectance and precipitation data, was applied to the probe of PG's climatic impacts. Results showed that PG, in the study area, has experienced a striking spatial expansion during the past 20 years, and more important, the expansion correlated strongly to the local climate change. It showed that the annual precipitation, in the study area, decreased during these years, which constrasts to a slightly increasing trend of the adjacent districts without PG construction. In addition, resulting from the greenhouse effect, PG area presented a harsher increase of surface temperature compared to the non-PG areas. Our study also telled that the evapotranspiration of PG area has been largely cutted down ascribing to the gas tightness of plastic materials, showing a decline around 40%. This indicates a way that the development of plastic-covered agriculture may contribute to the change of the local climate.

  18. The Aggregate Representation of Terrestrial Land Covers Within Global Climate Models (GCM)

    Science.gov (United States)

    Shuttleworth, W. James; Sorooshian, Soroosh

    1996-01-01

    This project had four initial objectives: (1) to create a realistic coupled surface-atmosphere model to investigate the aggregate description of heterogeneous surfaces; (2) to develop a simple heuristic model of surface-atmosphere interactions; (3) using the above models, to test aggregation rules for a variety of realistic cover and meteorological conditions; and (4) to reconcile biosphere-atmosphere transfer scheme (BATS) land covers with those that can be recognized from space; Our progress in meeting these objectives can be summarized as follows. Objective 1: The first objective was achieved in the first year of the project by coupling the Biosphere-Atmosphere Transfer Scheme (BATS) with a proven two-dimensional model of the atmospheric boundary layer. The resulting model, BATS-ABL, is described in detail in a Masters thesis and reported in a paper in the Journal of Hydrology Objective 2: The potential value of the heuristic model was re-evaluated early in the project and a decision was made to focus subsequent research around modeling studies with the BATS-ABL model. The value of using such coupled surface-atmosphere models in this research area was further confirmed by the success of the Tucson Aggregation Workshop. Objective 3: There was excellent progress in using the BATS-ABL model to test aggregation rules for a variety of realistic covers. The foci of attention have been the site of the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) in Kansas and one of the study sites of the Anglo-Brazilian Amazonian Climate Observational Study (ABRACOS) near the city of Manaus, Amazonas, Brazil. These two sites were selected because of the ready availability of relevant field data to validate and initiate the BATS-ABL model. The results of these tests are given in a Masters thesis, and reported in two papers. Objective 4: Progress far exceeded original expectations not only in reconciling BATS land covers with those that can be

  19. A rapid transition from ice covered CO2–rich waters to a biologically mediated CO2 sink in the eastern Weddell Gyre

    Directory of Open Access Journals (Sweden)

    W. Geibert

    2008-09-01

    Full Text Available Circumpolar Deep Water (CDW, locally called Warm Deep Water (WDW, enters the Weddell Gyre in the southeast, roughly at 25° E to 30° E. In December 2002 and January 2003 we studied the effect of entrainment of WDW on the fugacity of carbon dioxide (fCO2 and dissolved inorganic carbon (DIC in Weddell Sea surface waters. Ultimately the fCO2 difference across the sea surface drives air-sea fluxes of CO2. Deep CTD sections and surface transects of fCO2 were made along the Prime Meridian, a northwest-southeast section, and along 17° E to 23° E during cruise ANT XX/2 on FS Polarstern. Upward movement and entrainment of WDW into the winter mixed layer had significantly increased DIC and fCO2 below the sea ice along 0° W and 17° E to 23° E, notably in the southern Weddell Gyre. Nonetheless, the ice cover largely prevented outgassing of CO2 to the atmosphere. During and upon melting of the ice, biological activity rapidly reduced surface water fCO2 by up to 100 μatm, thus creating a sink for atmospheric CO2. Despite the tendency of the surfacing WDW to cause CO2 supersaturation, the Weddell Gyre may well be a CO2 sink on an annual basis due to this effective mechanism involving ice cover and ensuing biological fCO2 reduction. Dissolution of calcium carbonate (CaCO3 in melting sea ice may play a minor role in this rapid reduction of surface water fCO2.

  20. Classification of debris-covered glaciers and rock glaciers in the Andes of central Chile

    Science.gov (United States)

    Janke, Jason R.; Bellisario, Antonio C.; Ferrando, Francisco A.

    2015-07-01

    In the Dry Andes of Chile (17 to 35° S), debris-covered glaciers and rock glaciers are differentiated from true glaciers based on the percentage of surface debris cover, thickness of surface debris, and ice content. Internal ice is preserved by an insulating cover of thick debris, which acts as a storage reservoir to release water during the summer and early fall. These landforms are more numerous than glaciers in the central Andes; however, the existing legislation only recognizes uncovered or semicovered glaciers as a water resource. Glaciers, debris-covered glaciers, and rock glaciers are being altered or removed by mining operations to extract valuable minerals from the mountains. In addition, agricultural expansion and population growth in this region have placed additional demands on water resources. In a warmer climate, as glaciers recede and seasonal water availability becomes condensed over the course of a snowmelt season, rock glaciers and debris-covered glaciers contribute a larger component of base flow to rivers and streams. As a result, identifying and locating these features to implement sustainable regional planning for water resources is important. The objective of this study is to develop a classification system to identify debris-covered glaciers and rock glaciers based on the interpretation of satellite imagery and aerial photographs. The classification system is linked to field observations and measurements of ice content. Debris-covered glaciers have three subclasses: surface coverage of semi (class 1) and fully covered (class 2) glaciers differentiates the first two forms, whereas debris thickness is critical for class 3 when glaciers become buried with more than 3 m of surface debris. Based on field observations, the amount of ice decreases from more than 85%, to 65-85%, to 45-65% for semi, fully, and buried debris-covered glaciers, respectively. Rock glaciers are characterized by three stages. Class 4 rock glaciers have pronounced

  1. Effect of retreating sea ice on Arctic cloud cover in simulated recent global warming

    Directory of Open Access Journals (Sweden)

    M. Abe

    2016-11-01

    Full Text Available This study investigates the effect of sea ice reduction on Arctic cloud cover in historical simulations with the coupled atmosphere–ocean general circulation model MIROC5. Arctic sea ice has been substantially retreating since the 1980s, particularly in September, under simulated global warming conditions. The simulated sea ice reduction is consistent with satellite observations. On the other hand, Arctic cloud cover has been increasing in October, with about a 1-month lag behind the sea ice reduction. The delayed response leads to extensive sea ice reductions because the heat and moisture fluxes from the underlying open ocean into the atmosphere are enhanced. Sensitivity experiments with the atmospheric part of MIROC5 clearly show that sea ice reduction causes increases in cloud cover. Arctic cloud cover increases primarily in the lower troposphere, but it decreases in the near-surface layers just above the ocean; predominant temperature rises in these near-surface layers cause drying (i.e., decreases in relative humidity, despite increasing moisture flux. Cloud radiative forcing due to increases in cloud cover in autumn brings an increase in the surface downward longwave radiation (DLR by approximately 40–60 % compared to changes in clear-sky surface DLR in fall. These results suggest that an increase in Arctic cloud cover as a result of reduced sea ice coverage may bring further sea ice retreat and enhance the feedback processes of Arctic warming.

  2. A hybrid metaheuristic algorithm for the multi-depot covering tour vehicle routing problem

    NARCIS (Netherlands)

    Allahyari, S.; Salari, M.; Vigo, D.

    2015-01-01

    We propose a generalization of themulti-depot capacitated vehicle routing problem where the assumption of visiting each customer does not hold. In this problem, called the Multi-Depot Covering Tour Vehicle Routing Problem (MDCTVRP), the demand of each customer could be satisfied in two different

  3. Effectiveness of a ground-surface polymer membrane covering as a method for limiting infiltration into burial trenches at Maxey Flats, Kentucky

    International Nuclear Information System (INIS)

    Lyverse, M.A.

    1987-01-01

    The Maxey Flats Disposal Site (MFDS) was operated as a shallow land burial site for low-level radioactive wastes for a period of 14 years (1963-1977). In 1977, radionuclides were found to be migrating from a closed disposal trench into an adjacent newly constructed trench. This discovery prompted closure of the site. Over time, deterioration of the shale and clay cover on the trenches had resulted from subsidence due to the collapse of buried metallic containers and the decomposition of various organic wastes within the trenches. This subsidence increased infiltration of water into the trenches as surface water was retained over the waste in potholes and small ponds. Although infiltration rates to the waste increased, seepage rates of leachate out of the bottom and sides of the trenches were very slow due to the low permeability of surrounding native shale soils (average hydraulic conductivity 4 x 10 -3 ft/day). In 1981, a program was implemented to correct deficiencies and stabilize the site. This paper describes the effectiveness of one design method where a low permeable (hydraulic conductivity -9 ft/sec) polyvinylchloride membrane cover (PVC) 0.015 to 0.020 inches thick was placed over the burial trenches. The covers were installed over trenches beginning in the fall of 1981. Each trench is equipped with several sumps for the collection and removal of leachate. Water-level data were collected on sumps from five trenches during the study period May 1978 to October 1984, which spanned a period prior to and after installation of the PVC cover. 3 references, 4 figures, 1 table

  4. A Warming Surface but a Cooling Top of Atmosphere Associated with Warm, Moist Air Mass Advection over the Ice and Snow Covered Arctic

    Science.gov (United States)

    Sedlar, J.

    2015-12-01

    Atmospheric advection of heat and moisture from lower latitudes to the high-latitude Arctic is a critical component of Earth's energy cycle. Large-scale advective events have been shown to make up a significant portion of the moist static energy budget of the Arctic atmosphere, even though such events are typically infrequent. The transport of heat and moisture over surfaces covered by ice and snow results in dynamic changes to the boundary layer structure, stability and turbulence, as well as to diabatic processes such as cloud distribution, microphysics and subsequent radiative effects. Recent studies have identified advection into the Arctic as a key mechanism for modulating the melt and freeze of snow and sea ice, via modification to all-sky longwave radiation. This paper examines the radiative impact during summer of such Arctic advective events at the top of the atmosphere (TOA), considering also the important role they play for the surface energy budget. Using infrared sounder measurements from the AIRS satellite, the summer frequency of significantly stable and moist advective events from 2003-2014 are characterized; justification of AIRS profiles over the Arctic are made using radiosoundings during a 3-month transect (ACSE) across the Eastern Arctic basin. One such event was observed within the East Siberian Sea in August 2014 during ACSE, providing in situ verification on the robustness and capability of AIRS to monitor advective cases. Results will highlight the important surface warming aspect of stable, moist instrusions. However a paradox emerges as such events also result in a cooling at the TOA evident on monthly mean TOA radiation. Thus such events have a climatic importance over ice and snow covered surfaces across the Arctic. ERA-Interim reanalyses are examined to provide a longer term perspective on the frequency of such events as well as providing capability to estimate meridional fluxes of moist static energy.

  5. Comparison of connective tissue graft and guided tissue regeneration in covering root surfaces

    Directory of Open Access Journals (Sweden)

    LotfazarM.

    2002-08-01

    Full Text Available There are many researches evaluation different methods for covering the root surface. In the most of these studies, type I and II of Miller treatment had been searched. The purpose of this study was a comparison between connective tissue graft (CTG and guided tissue regeneration (GTR with a collagen membrane in the treatment of gingival recession defects (Miller class III. Six patients, each contributing a pair of Miller class III buccal gingival recessions, were treated. The clinical measurements were obtained at baseline and 1,2,4,6,12,18 months after surgery. Statistical analysis were performed using paired t-test between periods (baseline versus 6 months and baseline versus 18 months within each treatment group and also between treatment groups before treatment and 6, 12 and 18 months after the treatment. The treatments were compared by a triple analysis of variance along the time (treatment, patient, time. Both CTG and GTR with a bioabsorbable membrane demonstrated significant clinical and esthetic improvement for gingival recession coverage. The CTG and GTR procedures had mean root coverage of 55% and 47.5% respectively, in the end of study. The CTG group was statistically better than GTR for recession depth, recession width and keratinized tissue width. Also, passing the time (18 months as a distinct factor of treatment procedures was effective in increasing of clinical attachment level and keratinized tissue width.

  6. Decreasing cloud cover drives the recent mass loss on the Greenland Ice Sheet.

    Science.gov (United States)

    Hofer, Stefan; Tedstone, Andrew J; Fettweis, Xavier; Bamber, Jonathan L

    2017-06-01

    The Greenland Ice Sheet (GrIS) has been losing mass at an accelerating rate since the mid-1990s. This has been due to both increased ice discharge into the ocean and melting at the surface, with the latter being the dominant contribution. This change in state has been attributed to rising temperatures and a decrease in surface albedo. We show, using satellite data and climate model output, that the abrupt reduction in surface mass balance since about 1995 can be attributed largely to a coincident trend of decreasing summer cloud cover enhancing the melt-albedo feedback. Satellite observations show that, from 1995 to 2009, summer cloud cover decreased by 0.9 ± 0.3% per year. Model output indicates that the GrIS summer melt increases by 27 ± 13 gigatons (Gt) per percent reduction in summer cloud cover, principally because of the impact of increased shortwave radiation over the low albedo ablation zone. The observed reduction in cloud cover is strongly correlated with a state shift in the North Atlantic Oscillation promoting anticyclonic conditions in summer and suggests that the enhanced surface mass loss from the GrIS is driven by synoptic-scale changes in Arctic-wide atmospheric circulation.

  7. Carbon steel protection in G.S. (Girlder sulfide) plants. Iron sulfide scales formation on surfaces covered by fabrication produced films. Pt. 4

    International Nuclear Information System (INIS)

    Burkart, A.L.

    1986-04-01

    This work describes the assays aimed to passivate the steel carbon of the process pipings. This steel is marked by the ASTM A 333 G6 and is chemically similar to those of isotopic exchange towers which corrode in contact with in-water hydrogen sulfide solutions forming iron sulfide protective layers. The differences between both materials lie in the surface characteristics to be passivated. The steel of towers has an internal side covered by paint which shall be removed prior to passivation. The steel's internal side shall be covered by a film formed during the fabrication process and constituted by calcinated wastes and iron oxides (magnetite, hematite and wustite). This film interferes in the formation process of passivating layers of pyrrhotite and pyrite. The possibility to passivate the pipes in their actual state was evaluated since it would result highly laborious and expensive to eliminate the film. (Author) [es

  8. A computational study on the adsorption configurations and reactions of SiHx(x = 1-4) on clean and H-covered Si(100) surfaces

    Science.gov (United States)

    Le, Thong N.-M.; Raghunath, P.; Huynh, Lam K.; Lin, M. C.

    2016-11-01

    Possible adsorption configurations of H and SiHx (x = 1 - 4) on clean and H-covered Si(100) surfaces are determined by using spin-polarized DFT calculations. The results show that, on the clean surface, the gas-phase hydrogen atom and SiH3 radicals effectively adsorb on the top sites, while SiH and SiH2 prefer the bridge sites of the first layer. Another possibility for SiH is to reside on the hollow sites with a triple-bond configuration. For a partially H-coverd Si(100) surface, the mechanism is similar but with higher adsorption energies in most cases. This suggests that the surface species become more stable in the presence of surface hydrogens. The minimum energy paths for the adsorption/migration and reactions of H/SiHx species on the surfaces are explored using the climbing image-nudged elastic band method. The competitive surface processes for Si thin-film formation from SiHx precursors are also predicted. The study reveals that the migration of hydrogen adatom is unimportant with respect to leaving open surface sites because of its high barriers (>29.0 kcal/mol). Alternatively, the abstraction of hydrogen adatoms by H/SiHx radicals is more favorable. Moreover, the removal of hydrogen atoms from adsorbed SiHx, an essential step for forming Si layers, is dominated by abstraction rather than the decomposition processes.

  9. Final covering of the Ronneburg uranium mining site

    International Nuclear Information System (INIS)

    Hoepfner, Uwe

    2007-01-01

    The rehabilitation of WISMUT's former Ronneburg uranium mining site involves backfilling of waste rock to the Lichtenberg open pit. The relocation project comprises about 110 million m 3 of sulphide-bearing and AMD-generating waste rock which makes it the most important and most cost-intensive single surface restoration project conducted by WISMUT at the Ronneburg site. The backfilled waste rock has to be covered on an area of about 220 ha to control water infiltration and gas diffusion. Design planning for the final cover placement which began in 2004 had to be based on a comprehensive cost-benefit analysis as well on field tests of alternative cover options which are in compliance with legal requirements. An intensive testing program concerning the vadose zone of soil covers has therefore been started in 2000. The paper presents an overview of the monitoring program and the results of the vadose zone measurements. The water of soil covers have to be predicted for extended evaluation periods. Therefore water balance simulations of single layer covers (storage and evaporation concept) taking current and future soil and climate conditions into account are performed with the HYDRUS 2D code. (author)

  10. Effect of using different cover image quality to obtain robust selective embedding in steganography

    Science.gov (United States)

    Abdullah, Karwan Asaad; Al-Jawad, Naseer; Abdulla, Alan Anwer

    2014-05-01

    One of the common types of steganography is to conceal an image as a secret message in another image which normally called a cover image; the resulting image is called a stego image. The aim of this paper is to investigate the effect of using different cover image quality, and also analyse the use of different bit-plane in term of robustness against well-known active attacks such as gamma, statistical filters, and linear spatial filters. The secret messages are embedded in higher bit-plane, i.e. in other than Least Significant Bit (LSB), in order to resist active attacks. The embedding process is performed in three major steps: First, the embedding algorithm is selectively identifying useful areas (blocks) for embedding based on its lighting condition. Second, is to nominate the most useful blocks for embedding based on their entropy and average. Third, is to select the right bit-plane for embedding. This kind of block selection made the embedding process scatters the secret message(s) randomly around the cover image. Different tests have been performed for selecting a proper block size and this is related to the nature of the used cover image. Our proposed method suggests a suitable embedding bit-plane as well as the right blocks for the embedding. Experimental results demonstrate that different image quality used for the cover images will have an effect when the stego image is attacked by different active attacks. Although the secret messages are embedded in higher bit-plane, but they cannot be recognised visually within the stegos image.

  11. Monitoring cover crops using radar remote sensing in southern Ontario, Canada

    Science.gov (United States)

    Shang, J.; Huang, X.; Liu, J.; Wang, J.

    2016-12-01

    Information on agricultural land surface conditions is important for developing best land management practices to maintain the overall health of the fields. The climate condition supports one harvest per year for the majority of the field crops in Canada, with a relative short growing season between May and September. During the non-growing-season months (October to the following April), many fields are traditionally left bare. In more recent year, there has been an increased interest in planting cover crops. Benefits of cover crops include boosting soil organic matters, preventing soil from erosion, retaining soil moisture, and reducing surface runoff hence protecting water quality. Optical remote sensing technology has been exploited for monitoring cover crops. However limitations inherent to optical sensors such as cloud interference and signal saturation (when leaf area index is above 2.5) impeded its operational application. Radar remote sensing on the other hand is not hindered by unfavorable weather conditions, and the signal continues to be sensitive to crop growth beyond the saturation point of optical sensors. It offers a viable means for capturing timely information on field surface conditions (with or without crop cover) or crop development status. This research investigated the potential of using multi-temporal RADARSAT-2 C-band synthetic aperture radar (SAR) data collected in 2015 over multiple fields of winter wheat, corn and soybean crops in southern Ontario, Canada, to retrieve information on the presence of cover crops and their growth status. Encouraging results have been obtained. This presentation will report the methodology developed and the results obtained.

  12. Characteristics of snow cover duration across the northeast United States of America

    Science.gov (United States)

    Leathers, Daniel J.; Luff, Barbara L.

    1997-11-01

    The presence or absence of a snow cover affects a myriad of environmental and societal systems through its modification of the surface radiation balance and its ultimate impact on near-surface air temperatures. Daily snow cover data were collected for a network of 91 stations covering the northeast USA from Maine, south through to West Virginia. The snow cover data along with ancillary temperature, snowfall and precipitation data were used to investigate the characteristics of snow cover duration in this region and the effects of the snow cover on boundary layer climate variables for the snow cover seasons 1948-1949 through to 1987-1988.Results indicate that snow cover duration is variable in both space and time. The duration of a snow cover of 2.5 cm or greater varies from greater than 100 days in northern New England to less than 20 days across areas of Delaware, Maryland and West Virginia. Temporally, snow cover duration for the region as a whole was very short from the late 1940s through to the mid-1950s. From the late 1950s to the end of the period snow cover duration has varied around a consistent mean value. No long-term trends in snow cover duration are apparent in the record for the northeast USA.Principal components analysis and clustering techniques were utilized to isolate spatially coherent regions in which snow cover duration has varied similarly over the period of record. This analysis resulted in the identification of four snow-cover-duration regions across the northeast USA: including (i) the West Virginia area, (ii) the mid-Atlantic from southern New England through to western Pennsylvania, (iii) western and central New York and (iv) northern New England. Snow cover duration is shown to be highly associated with snowfall and temperature but not strongly related to total liquid precipitation. The intra-annual variability of snow cover duration is also investigated for each region.

  13. The Regional Land Cover Monitoring System: Building regional capacity through innovative land cover mapping approaches

    Science.gov (United States)

    Saah, D.; Tenneson, K.; Hanh, Q. N.; Aekakkararungroj, A.; Aung, K. S.; Goldstein, J.; Cutter, P. G.; Maus, P.; Markert, K. N.; Anderson, E.; Ellenburg, W. L.; Ate, P.; Flores Cordova, A. I.; Vadrevu, K.; Potapov, P.; Phongsapan, K.; Chishtie, F.; Clinton, N.; Ganz, D.

    2017-12-01

    Earth observation and Geographic Information System (GIS) tools, products, and services are vital to support the environmental decision making by governmental institutions, non-governmental agencies, and the general public. At the heart of environmental decision making is the monitoring land cover and land use change (LCLUC) for land resource planning and for ecosystem services, including biodiversity conservation and resilience to climate change. A major challenge for monitoring LCLUC in developing regions, such as Southeast Asia, is inconsistent data products at inconsistent intervals that have different typologies across the region and are typically made in without stakeholder engagement or input. Here we present the Regional Land Cover Monitoring System (RLCMS), a novel land cover mapping effort for Southeast Asia, implemented by SERVIR-Mekong, a joint NASA-USAID initiative that brings Earth observations to improve environmental decision making in developing countries. The RLCMS focuses on mapping biophysical variables (e.g. canopy cover, tree height, or percent surface water) at an annual interval and in turn using those biophysical variables to develop land cover maps based on stakeholder definitions of land cover classes. This allows for flexible and consistent land cover classifications that can meet the needs of different institutions across the region. Another component of the RLCMS production is the stake-holder engagement through co-development. Institutions that directly benefit from this system have helped drive the development for regional needs leading to services for their specific uses. Examples of services for regional stakeholders include using the RLCMS to develop maps using the IPCC classification scheme for GHG emission reporting and developing custom annual maps as an input to hydrologic modeling/flood forecasting systems. In addition to the implementation of this system and the service stemming from the RLCMS in Southeast Asia, it is

  14. In-vitro interactions of human chondrocytes and mesenchymal stem cells, and of mouse macrophages with phospholipid-covered metallic implant materials

    Directory of Open Access Journals (Sweden)

    R Willumeit

    2007-03-01

    Full Text Available Phospholipid-coatings on metallic implant surfaces were evaluated in terms of adhesion, proliferation and matrix production of skeletal cells, and of macrophage stimulation. The working hypothesis is that mimicking a model biomembrane by phospholipids on surfaces to which cells adhere, the surface recognition by surrounding cells is altered. In this study, 1 mirror-like polished Ti-6Al-7Nb and 2 porous Ti-6Al-4V specimens were covered with the phospholipids POPE (palmitoyl-oleoyl phosphatidyl-ethanolamine and POPC (palmitoyl-oleoyl phosphatidyl-choline, and the interactions of a human articular chondrocytes (HAC, b human mesenchymal stem cells (HMSC, and c mouse macrophages (RAW 264.7 were tested in vitro. On POPE-covered polished surfaces adherence of HAC (42% of seeded cells after 2 hrs and metabolic activity (MTT after 3 days were reduced, while on porous surfaces 99% HAC adhered, and metabolic activity was significantly increased, compared to respective native surfaces. On both POPE-covered surfaces the chondrocyte phenotype was present. After 3 weeks of chondrogenic differentiation, cartilage matrix production (measuring chondroitin sulphate per HAC number was significantly increased by about 30% on both POPE-covered metallic surfaces. On both POPC-covered surfaces nearly no adhering and surviving HAC were found. HMSC grown on POPE-covered porous substrates showed osteogenic differentiation by improved osteopontin and collagen I expression in RT-PCR, and osteocalcin fluorescence and bone nodule formation was only detectable on POPE-covered porous surfaces. In contrast to POPC and other phospholipids used as positive controls, POPE did not stimulate the NO production in mouse macrophage cultures. We therefore conclude that a phospholipid coating by POPE shows potential as surface modification for metallic implant materials.

  15. Effects of bryophyte and lichen cover on permafrost soil temperature at large scale

    Directory of Open Access Journals (Sweden)

    P. Porada

    2016-09-01

    Full Text Available Bryophyte and lichen cover on the forest floor at high latitudes exerts an insulating effect on the ground. In this way, the cover decreases mean annual soil temperature and can protect permafrost soil. Climate change, however, may change bryophyte and lichen cover, with effects on the permafrost state and related carbon balance. It is, therefore, crucial to predict how the bryophyte and lichen cover will react to environmental change at the global scale. To date, current global land surface models contain only empirical representations of the bryophyte and lichen cover, which makes it impractical to predict the future state and function of bryophytes and lichens. For this reason, we integrate a process-based model of bryophyte and lichen growth into the global land surface model JSBACH (Jena Scheme for Biosphere–Atmosphere Coupling in Hamburg. The model simulates bryophyte and lichen cover on upland sites. Wetlands are not included. We take into account the dynamic nature of the thermal properties of the bryophyte and lichen cover and their relation to environmental factors. Subsequently, we compare simulations with and without bryophyte and lichen cover to quantify the insulating effect of the organisms on the soil. We find an average cooling effect of the bryophyte and lichen cover of 2.7 K on temperature in the topsoil for the region north of 50° N under the current climate. Locally, a cooling of up to 5.7 K may be reached. Moreover, we show that using a simple, empirical representation of the bryophyte and lichen cover without dynamic properties only results in an average cooling of around 0.5 K. This suggests that (a bryophytes and lichens have a significant impact on soil temperature in high-latitude ecosystems and (b a process-based description of their thermal properties is necessary for a realistic representation of the cooling effect. The advanced land surface scheme, including a dynamic bryophyte and lichen model, will

  16. Radiative warming of the air observed near a bare-soil surface on calm clear nights

    International Nuclear Information System (INIS)

    Sang, N.; Kobayahsi, T.

    1999-01-01

    The radiative flux in the lowest three meters above a bare-soil surface was directly measured on calm nights with little cloud cover. Although divergence of upward radiative flux occurred above 1m, convergence was often observed between 0.2m and 1m all through the night. Almost the same results were obtained for the net flux except that the transitional height between divergence and convergence was some tens of centimeters, which means that radiative warming occurred just above the bare-soil surface during the night. This phenomenon can be explained by postulating that cold air is produced by conduction at the surface of small heat-insulated projections (HIPs) such as soil grains on the ground surface, while the ground releases the heat stored during the day by radiation through the pores between HIPs and warms the air immediately above the surface at night. This “HIP hypothesis” can also account for the so-called “raised minimum (RM)” phenomenon. (author)

  17. Surface Mining and Reclamation Effects on Flood Response of Watersheds in the Central Appalachian Plateau Region

    Science.gov (United States)

    Ferrari, J. R.; Lookingbill, T. R.; McCormick, B.; Townsend, P. A.; Eshleman, K. N.

    2009-01-01

    Surface mining of coal and subsequent reclamation represent the dominant land use change in the central Appalachian Plateau (CAP) region of the United States. Hydrologic impacts of surface mining have been studied at the plot scale, but effects at broader scales have not been explored adequately. Broad-scale classification of reclaimed sites is difficult because standing vegetation makes them nearly indistinguishable from alternate land uses. We used a land cover data set that accurately maps surface mines for a 187-km2 watershed within the CAP. These land cover data, as well as plot-level data from within the watershed, are used with HSPF (Hydrologic Simulation Program-Fortran) to estimate changes in flood response as a function of increased mining. Results show that the rate at which flood magnitude increases due to increased mining is linear, with greater rates observed for less frequent return intervals. These findings indicate that mine reclamation leaves the landscape in a condition more similar to urban areas rather than does simple deforestation, and call into question the effectiveness of reclamation in terms of returning mined areas to the hydrological state that existed before mining.

  18. Control of water infiltration into near surface LLW [low-level radioactive waste] disposal units

    International Nuclear Information System (INIS)

    Schulz, R.K.; Ridky, R.W.; O'Donnell, E.O.

    1990-12-01

    Three kinds of waste disposal unit covers a barriers to water infiltration are being investigated. They are: (1) resistive layer barrier, (2) conductive layer barrier, and (3) bioengineering management. The resistive layer barrier consists of compacted earthen material (e.g. clay). The conductive layer barrier consists of a conductive layer in conjunction with a capillary break. As long as unsaturated flow conditions are maintained the conductive layer will wick water around the capillary break. Below grade layered covers such as (1) and (2) will fail if there is appreciable subsidence of the cover. Remedial action for this kind of failure will be difficult. A surface cover, called bioengineering management, is meant to overcome this problem. The bioengineering management surface barrier is easily repairable if damaged by subsidence; therefore, it could be the system of choice under active subsidence conditions. The bioengineering management procedure also has been shown to be effective in dewatering saturated trenches and could be used for remedial action efforts. After cessation of subsidence, that procedure could be replaced by a resistive layer barrier, or perhaps even better, a resistive layer barrier/conductive layer barrier system. This latter system would then give long-term effective protection against water entry to waste and without institutional care. These various concepts are being assessed in six large (70ft x 45ft x 10ft each) lysimeters at Beltsville, Maryland. 6 refs., 20 figs.,

  19. Seepage through a hazardous-waste trench cover

    Science.gov (United States)

    Healy, R.W.

    1989-01-01

    Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216 mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest rates occurred along the edge of the cover, where seepage was highly episodic, with 84% of the total there being traced to wetting fronts from 28 individual storms. Limitations of the zero-flux-plane method were severe enough for the method to be judged inappropriate for use in this study.Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest

  20. Electronic excitation of Ti atoms sputtered by energetic Ar+ and He+ from clean and monolayer oxygen covered surfaces

    International Nuclear Information System (INIS)

    Pellin, M.J.; Gruen, D.M.; Young, C.E.; Wiggins, M.D.; Argonne National Lab., IL

    1983-01-01

    Electronic excitation of Ti atoms ejected during energetic ion bombardment (Ar + , He + ) of well characterized clean and oxygen covered polycrystalline Ti metal surfaces has been determined. For states with 0 to 2 eV and 3 to 5.5 eV of electronic energy, static mode laser fluorescence spectroscopy (LFS) and static mode spontaneous fluorescence spectroscopy (SFS) were used respectively. These experiments which were carried out in a UHV ( -10 Torr) system equipped with an Auger spectrometer provide measurements of the correlation between oxygen coverage (0 to 3 monolayers) and the excited state distribution of sputtered Ti atoms. The experimentally determined electronic partition function of Ti atoms does not show an exponential dependence on energy (E) above the ground state but rather an E -2 or E -3 power law dependence. (orig.)

  1. Using Winter Annual Cover Crops in a Virginia No-till Cotton Production System

    OpenAIRE

    Daniel, James B. II

    1997-01-01

    Cotton (Gossypium hirsutum L.) is a low residue crop, that may not provide sufficient surface residue to reduce erosion and protect the soil. A winter annual cover crop could alleviate erosion between cotton crops. Field experiments were conducted to evaluate selected winter annual cover crops for biomass production, ground cover, and N assimilation. The cover crop treatments were monitored under no-till and conventional tillage systems for the effects on soil moisture, cotton yield and qu...

  2. Morphology and grain structure evolution during epitaxial growth of Ag films on native-oxide-covered Si surface

    International Nuclear Information System (INIS)

    Hur, Tae-Bong; Kim, Hong Koo; Perello, David; Yun, Minhee; Kulovits, Andreas; Wiezorek, Joerg

    2008-01-01

    Epitaxial nanocrystalline Ag films were grown on initially native-oxide-covered Si(001) substrates using radio-frequency magnetron sputtering. Mechanisms of grain growth and morphology evolution were investigated. An epitaxially oriented Ag layer (∼5 nm thick) formed on the oxide-desorbed Si surface during the initial growth phase. After a period of growth instability, characterized as kinetic roughening, grain growth stagnation, and increase of step-edge density, a layer of nanocrystalline Ag grains with a uniform size distribution appeared on the quasi-two-dimensional layer. This hierarchical process of film formation is attributed to the dynamic interplay between incoming energetic Ag particles and native oxide. The cyclic interaction (desorption and migration) of the oxide with the growing Ag film is found to play a crucial role in the characteristic evolution of grain growth and morphology change involving an interval of grain growth stagnation

  3. Perceiving a calling, living a calling, and job satisfaction: testing a moderated, multiple mediator model.

    Science.gov (United States)

    Duffy, Ryan D; Bott, Elizabeth M; Allan, Blake A; Torrey, Carrie L; Dik, Bryan J

    2012-01-01

    The current study examined the relation between perceiving a calling, living a calling, and job satisfaction among a diverse group of employed adults who completed an online survey (N = 201). Perceiving a calling and living a calling were positively correlated with career commitment, work meaning, and job satisfaction. Living a calling moderated the relations of perceiving a calling with career commitment and work meaning, such that these relations were more robust for those with a stronger sense they were living their calling. Additionally, a moderated, multiple mediator model was run to examine the mediating role of career commitment and work meaning in the relation of perceiving a calling and job satisfaction, while accounting for the moderating role of living a calling. Results indicated that work meaning and career commitment fully mediated the relation between perceiving a calling and job satisfaction. However, the indirect effects of work meaning and career commitment were only significant for individuals with high levels of living a calling, indicating the importance of living a calling in the link between perceiving a calling and job satisfaction. Implications for research and practice are discussed. (c) 2012 APA, all rights reserved.

  4. Call Center Capacity Planning

    DEFF Research Database (Denmark)

    Nielsen, Thomas Bang

    in order to relate the results to the service levels used in call centers. Furthermore, the generic nature of the approximation is demonstrated by applying it to a system incorporating a dynamic priority scheme. In the last paper Optimization of overflow policies in call centers, overflows between agent......The main topics of the thesis are theoretical and applied queueing theory within a call center setting. Call centers have in recent years become the main means of communication between customers and companies, and between citizens and public institutions. The extensively computerized infrastructure...... in modern call centers allows for a high level of customization, but also induces complicated operational processes. The size of the industry together with the complex and labor intensive nature of large call centers motivates the research carried out to understand the underlying processes. The customizable...

  5. Pit formation on stainless steel surfaces pre-treated with biosurfactants produced by Pseudomonas fluorescens

    International Nuclear Information System (INIS)

    Dagbert, Catherine; Meylheuc, Thierry; Bellon-Fontaine, Marie-Noelle

    2008-01-01

    Today, it is widely established that the surface tension of water can be reduced by some microorganisms capable of synthesizing surface-active compounds called biosurfactants (BS). BS characteristics depend on the microorganism that produces them and therefore, on the microorganism culture conditions. Some studies on chemical surfactants have shown that the adsorption of surface-active compounds plays a major role in corrosion; indeed they are used as a good corrosion inhibition tool. The purpose of this study was first, to estimate the importance and behavior of the stainless steels passive film on the adsorption of BS, produced by the Gram negative bacteria Pseudomonas fluorescens, and secondly, to study the impact of these treatments on the pitting corrosion. In this paper, the galvanostatic polarization technique, used as accelerated method for determining the characteristic pit potentials on stainless steels, is examined. Pit growth, shape and cover formation were also observed. The surface topography of the corroded specimens was investigated using field emission scanning electron microscopy (FESEM)

  6. Pit formation on stainless steel surfaces pre-treated with biosurfactants produced by Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Dagbert, Catherine [ECP-LGPM, Grande Voie des Vignes, 92295 Chatenay-Malabry (France)], E-mail: catherine.dagbert@ecp.fr; Meylheuc, Thierry; Bellon-Fontaine, Marie-Noelle [INRA, UMR 763 Bioadhesion et Hygiene des Materiaux, F-91300 Massy (France); AGROPARISTECH, UMR 763 Bioadhesion et Hygiene des Materiaux, F-91300 Massy (France)

    2008-12-01

    Today, it is widely established that the surface tension of water can be reduced by some microorganisms capable of synthesizing surface-active compounds called biosurfactants (BS). BS characteristics depend on the microorganism that produces them and therefore, on the microorganism culture conditions. Some studies on chemical surfactants have shown that the adsorption of surface-active compounds plays a major role in corrosion; indeed they are used as a good corrosion inhibition tool. The purpose of this study was first, to estimate the importance and behavior of the stainless steels passive film on the adsorption of BS, produced by the Gram negative bacteria Pseudomonas fluorescens, and secondly, to study the impact of these treatments on the pitting corrosion. In this paper, the galvanostatic polarization technique, used as accelerated method for determining the characteristic pit potentials on stainless steels, is examined. Pit growth, shape and cover formation were also observed. The surface topography of the corroded specimens was investigated using field emission scanning electron microscopy (FESEM)

  7. Calle Blanco

    Directory of Open Access Journals (Sweden)

    Gonzalo Cerda Brintrup

    1988-06-01

    Full Text Available Importante arteria, que comunica el sector del puerto con la plaza. Las más imponentes construcciones se sucedían de un modo continuo, encaramándose a ambos lados de la empinada calle. Antes del gran incendio de 1936 grandes casonas de madera destacaban en calle Irarrázabal y en la esquina de ésta con calle Blanco, la más hermosa construcción pertenecía a don Alberto Oyarzún y la casa vecina hacia Blanco era de don Mateo Miserda, limitada por arriba con la casa de don Augusto Van Der Steldt y ésta era seguida de la casa de don David Barrientos provista de cuatro cúpulas en las esquinas y de un amplio corredor en el frontis. Todas estas construcciones de madera fueron destruidas en el gran incendio de 1936.

  8. Soil cover by natural trees in agroforestry systems

    Science.gov (United States)

    Diaz-Ambrona, C. G. H.; Almoguera Millán, C.; Tarquis Alfonso, A.

    2009-04-01

    The dehesa is common agroforestry system in the Iberian Peninsula. These open oak parklands with silvo-pastoral use cover about two million hectares. Traditionally annual pastures have been grazed by cows, sheep and also goats while acorns feed Iberian pig diet. Evergreen oak (Quercus ilex L.) has other uses as fuelwood collection and folder after tree pruning. The hypothesis of this work is that tree density and canopy depend on soil types. We using the spanish GIS called SIGPAC to download the images of dehesa in areas with different soil types. True colour images were restoring to a binary code, previously canopy colour range was selected. Soil cover by tree canopy was calculated and number of trees. Processing result was comparable to real data. With these data we have applied a dynamic simulation model Dehesa to determine evergreen oak acorn and annual pasture production. The model Dehesa is divided into five submodels: Climate, Soil, Evergreen oak, Pasture and Grazing. The first three require the inputs: (i) daily weather data (maximum and minimum temperatures, precipitation and solar radiation); (ii) the soil input parameters for three horizons (thickness, field capacity, permanent wilting point, and bulk density); and (iii) the tree characterization of the dehesa (tree density, canopy diameter and height, and diameter of the trunk). The influence of tree on pasture potential production is inversely proportional to the canopy cover. Acorn production increase with tree canopy cover until stabilizing itself, and will decrease if density becomes too high (more than 80% soil tree cover) at that point there is competition between the trees. Main driving force for dehesa productivity is soil type for pasture, and tree cover for acorn production. Highest pasture productivity was obtained on soil Dystric Planosol (Alfisol), Dystric Cambisol and Chromo-calcic-luvisol, these soils only cover 22.4% of southwest of the Iberian peninssula. Lowest productivity was

  9. Surface studies on graphite furnace platforms covered with Pd, Rh and Ir as modifiers in graphite furnace atomic absorption spectrometry of tellurium

    Energy Technology Data Exchange (ETDEWEB)

    Pedro, Juana [Area de Química Analítica, Departamento de Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Stripekis, Jorge [Laboratorio de Análisis de Trazas, Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina); Departamento de Ingeniería Química, Instituto Tecnológico de Buenos Aires, Av. Eduardo Madero 399 (1106), Buenos Aires (Argentina); Bonivardi, Adrian [Area de Química Analítica, Departamento de Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Tudino, Mabel, E-mail: tudino@qi.fcen.uba.ar [Laboratorio de Análisis de Trazas, Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina)

    2015-05-01

    The main objective of this work is the study of correlations between the efficiency of the distribution of the permanent platinum group modifiers Pd, Rh and Ir over the graphite surface with the aim of improving analytical signal of tellurium. Modifier solution was deposited onto the platform and pyrolysed after drying. In the case of Pd, the physical vaporization/deposition technique was also tested. In order to analyze the differences amongst coverings (morphology, topology and distribution), the graphite surfaces were studied with scanning electron microscopy and energy dispersive X-ray microscopy. Micrographs for physical vaporization and pyrolytic deposition of Pd were also analyzed in order to explain the lack of signal obtained for tellurium with the first alternative. Similar micrographs were obtained for pyrolytic deposition of Ir and Rh and then, compared to those of Pd. Ir showed the most homogeneous distribution on the graphite surface and the tallest and sharpest transient. With the aim of improving the analytical signal of tellurium, the correlation between the surface studies and the tellurium transient signal (height, area and shape) is discussed. - Highlights: • Distribution of Rh, Pd and Ir onto graphite furnaces is evaluated by SEM and EDX • Micrographs and spectra showed that surface distribution could influence Te signal. • Ir showed the best signal together with the most homogeneous surface distribution. • Pd-PVD micrographs revealed the absence of graphite and no signal for Te.

  10. Oral mucosa tissue response to titanium cover screws.

    Science.gov (United States)

    Olmedo, Daniel G; Paparella, María L; Spielberg, Martín; Brandizzi, Daniel; Guglielmotti, María B; Cabrini, Rómulo L

    2012-08-01

    Titanium is the most widely used metal in dental implantology. The release of particles from metal structures into the biologic milieu may be the result of electrochemical processes (corrosion) and/or mechanical disruption during insertion, abutment connection, or removal of failing implants. The aim of the present study is to evaluate tissue response of human oral mucosa adjacent to titanium cover screws. One hundred fifty-three biopsies of the supra-implant oral mucosa adjacent to the cover screw of submerged dental implants were analyzed. Histologic studies were performed to analyze epithelial and connective tissue as well as the presence of metal particles, which were identified using microchemical analysis. Langerhans cells, macrophages, and T lymphocytes were studied using immunohistochemical techniques. The surface of the cover screws was evaluated by scanning electron microscopy (SEM). Forty-one percent of mucosa biopsies exhibited metal particles in different layers of the section thickness. Particle number and size varied greatly among specimens. Immunohistochemical study confirmed the presence of macrophages and T lymphocytes associated with the metal particles. Microchemical analysis revealed the presence of titanium in the particles. On SEM analysis, the surface of the screws exhibited depressions and irregularities. The biologic effects seen in the mucosa in contact with the cover screws might be associated with the presence of titanium or other elements, such as aluminum or vanadium. The potential long-term biologic effects of particles on soft tissues adjacent to metallic devices should be further investigated because these effects might affect the clinical outcome of the implant.

  11. Multi-temporal high resolution monitoring of debris-covered glaciers using unmanned aerial vehicles

    Science.gov (United States)

    Kraaijenbrink, Philip; Immerzeel, Walter; de Jong, Steven; Shea, Joseph; Pellicciotti, Francesca; Meijer, Sander; Shresta, Arun

    2016-04-01

    Debris-covered glaciers in the Himalayas are relatively unstudied due to the difficulties in fieldwork caused by the inaccessible terrain and the presence of debris layers, which complicate in situ measurements. To overcome these difficulties an unmanned aerial vehicle (UAV) has been deployed multiple times over two debris covered glaciers in the Langtang catchment, located in the Nepalese Himalayas. Using differential GPS measurements and the Structure for Motion algorithm the UAV imagery was processed into accurate high-resolution digital elevation models and orthomosaics for both pre- and post-monsoon periods. These data were successfully used to estimate seasonal surface flow and mass wasting by using cross-correlation feature tracking and DEM differencing techniques. The results reveal large heterogeneity in mass loss and surface flow over the glacier surfaces, which are primarily caused by the presence of surface features such as ice cliffs and supra-glacial lakes. Accordingly, we systematically analyze those features using an object-based approach and relate their characteristics to the observed dynamics. We show that ice cliffs and supra-glacial lakes are contributing to a significant portion of the melt water of debris covered glaciers and we conclude that UAVs have great potential in understanding the key surface processes that remain largely undetected by using satellite remote sensing.

  12. Remote Sensing of Urban Land Cover/Land Use Change, Surface Thermal Responses, and Potential Meteorological and Climate Change Impacts

    Science.gov (United States)

    Quattrochi, Dale A.; Jedlovec, Gary; Meyer, Paul

    2011-01-01

    City growth influences the development of the urban heat island (UHI), but the effect that local meteorology has on the UHI is less well known. This paper presents some preliminary findings from a study that uses multitemporal Landsat TM and ASTER data to evaluate land cover/land use change (LULCC) over the NASA Marshall Space Flight Center (MFSC) and its Huntsville, AL metropolitan area. Landsat NLCD data for 1992 and 2001 have been used to evaluate LULCC for MSFC and the surrounding urban area. Land surface temperature (LST) and emissivity derived from NLCD data have also been analyzed to assess changes in these parameters in relation to LULCC. Additionally, LULCC, LST, and emissivity have been identified from ASTER data from 2001 and 2011 to provide a comparison with the 2001 NLCD and as a measure of current conditions within the study area. As anticipated, the multi-temporal NLCD and ASTER data show that significant changes have occurred in land covers, LST, and emissivity within and around MSFC. The patterns and arrangement of these changes, however, is significant because the juxtaposition of urban land covers within and outside of MSFC provides insight on what impacts at a local to regional scale, the inter-linkage of these changes potentially have on meteorology. To further analyze these interactions between LULCC, LST, and emissivity with the lower atmosphere, a network of eleven weather stations has been established across the MSFC property. These weather stations provide data at a 10 minute interval, and these data are uplinked for use by MSFC facilities operations and the National Weather Service. The weather data are also integrated within a larger network of meteorological stations across north Alabama. Given that the MSFC weather stations will operate for an extended period of time, they can be used to evaluate how the building of new structures, and changes in roadways, and green spaces as identified in the MSFC master plan for the future, will

  13. Swine manure injection with low-disturbance applicator and cover crops reduce phosphorus losses.

    Science.gov (United States)

    Kovar, J L; Moorman, T B; Singer, J W; Cambardella, C A; Tomer, M D

    2011-01-01

    Injection of liquid swine manure disturbs surface soil so that runoff from treated lands can transport sediment and nutrients to surface waters. We determined the effect of two manure application methods on P fate in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] production system, with and without a winter rye (Secale cereale L.)-oat (Avena sativa L.) cover crop. Treatments included: (i) no manure; (ii) knife injection; and (iii) low-disturbance injection, each with and without the cover crop. Simulated rainfall runoff was analyzed for dissolved reactive P (DRP) and total P (TP). Rainfall was applied 8 d after manure application (early November) and again in May after emergence of the corn crop. Manure application increased soil bioavailable P in the 20- to 30-cm layer following knife injection and in the 5- to 20-cm layer following low-disturbance injection. The low-disturbance system caused less damage to the cover crop, so that P uptake was more than threefold greater. Losses of DRP were greater in both fall and spring following low-disturbance injection; however, application method had no effect on TP loads in runoff in either season. The cover crop reduced fall TP losses from plots with manure applied by either method. In spring, DRP losses were significantly higher from plots with the recently killed cover crop, but TP losses were not affected. Low-disturbance injection of swine manure into a standing cover crop can minimize plant damage and P losses in surface runoff while providing optimum P availability to a subsequent agronomic crop.

  14. Moduli of Riemann surfaces, transcendental aspects

    International Nuclear Information System (INIS)

    Hain, R.

    2000-01-01

    These notes are an informal introduction to moduli spaces of compact Riemann surfaces via complex analysis, topology and Hodge Theory. The prerequisites for the first lecture are just basic complex variables, basic Riemann surface theory up to at least the Riemann-Roch formula, and some algebraic topology, especially covering space theory. The first lecture covers moduli in genus 0 and genus 1 as these can be understood using relatively elementary methods, but illustrate many of the points which arise in higher genus. The notes cover more material than was covered in the lectures, and sometimes the order of topics in the notes differs from that in the lectures. We have seen in genus 1 case that M 1 is the quotient Γ 1 /X 1 of a contractible complex manifold X 1 = H by a discrete group Γ 1 = SL 2 (Z). The action of Γ 1 on X 1 is said to be virtually free - that is, Γ 1 has a finite index subgroup which acts (fixed point) freely on X 1 . In this section we will generalize this to all g >= 1 - we will sketch a proof that there is a contractible complex manifold Xg, called Teichmueller space, and a group Γ g , called the mapping class group, which acts virtually freely on X g . The moduli space of genus g compact Riemann surfaces is the quotient: M g = Γ g /X g . This will imply that M g has the structure of a complex analytic variety with finite quotient singularities. Teichmueller theory is a difficult and technical subject. Because of this, it is only possible to give an overview. In this lecture, we compute the orbifold Picard group of M g for all g >= 1. Recall that an orbifold line bundle over M g is a holomorphic line bundle L over Teichmueller space X g together with an action of the mapping class group Γ g on it such that the projection L → X g is Γ g -equivariant. An orbifold section of this line bundle is a holomorphic Γ g -equivariant section X g → L of L. This is easily seen to be equivalent to fixing a level l>= 3 and considering holomorphic

  15. Porous Silicon Covered with Silver Nanoparticles as Surface-Enhanced Raman Scattering (SERS) Substrate for Ultra-Low Concentration Detection.

    Science.gov (United States)

    Kosović, Marin; Balarin, Maja; Ivanda, Mile; Đerek, Vedran; Marciuš, Marijan; Ristić, Mira; Gamulin, Ozren

    2015-12-01

    Microporous and macro-mesoporous silicon templates for surface-enhanced Raman scattering (SERS) substrates were produced by anodization of low doped p-type silicon wafers. By immersion plating in AgNO3, the templates were covered with silver metallic film consisting of different silver nanostructures. Scanning electron microscopy (SEM) micrographs of these SERS substrates showed diverse morphology with significant difference in an average size and size distribution of silver nanoparticles. Ultraviolet-visible-near-infrared (UV-Vis-NIR) reflection spectroscopy showed plasmonic absorption at 398 and 469 nm, which is in accordance with the SEM findings. The activity of the SERS substrates was tested using rhodamine 6G (R6G) dye molecules and 514.5 nm laser excitation. Contrary to the microporous silicon template, the SERS substrate prepared from macro-mesoporous silicon template showed significantly broader size distribution of irregular silver nanoparticles as well as localized surface plasmon resonance closer to excitation laser wavelength. Such silver morphology has high SERS sensitivity that enables ultralow concentration detection of R6G dye molecules up to 10(-15) M. To our knowledge, this is the lowest concentration detected of R6G dye molecules on porous silicon-based SERS substrates, which might even indicate possible single molecule detection.

  16. Landscape correlates along mourning dove call-count routes in Mississippi

    Science.gov (United States)

    Elmore, R.D.; Vilella, F.J.; Gerard, P.D.

    2007-01-01

    Mourning dove (Zenaida macroura) call-count surveys in Mississippi, USA, suggest declining populations. We used available mourning dove call-count data to evaluate long-term mourning dove habitat relationships. Dove routes were located in the Mississippi Alluvial Valley, Deep Loess Province, Mid Coastal Plain, and Hilly Coastal Plain physiographic provinces of Mississippi. We also included routes in the Blackbelt Prairie region of Mississippi and Alabama, USA. We characterized landscape structure and composition within 1.64-km buffers around 10 selected mourning dove call-count routes during 3 time periods. Habitat classes included agriculture, forest, urban, regeneration stands, wetland, and woodlot. We used Akaike's Information Criterion to select the best candidate model. We selected a model containing percent agriculture and edge density that contained approximately 40% of the total variability in the data set. Percent agriculture was positively correlated with relative dove abundance. Interestingly, we found a negative relationship between edge density and dove abundance. Researchers should conduct future research on dove nesting patterns in Mississippi and threshold levels of edge necessary to maximize dove density. During the last 20 years, Mississippi lost more than 800,000 ha of cropland while forest cover represented largely by pine (Pinus taeda) plantations increased by more than 364,000 ha. Our results suggest observed localized declines in mourning dove abundance in Mississippi may be related to the documented conversion of agricultural lands to pine plantations.

  17. Annual land cover change mapping using MODIS time series to improve emissions inventories.

    Science.gov (United States)

    López Saldaña, G.; Quaife, T. L.; Clifford, D.

    2014-12-01

    Understanding and quantifying land surface changes is necessary for estimating greenhouse gas and ammonia emissions, and for meeting air quality limits and targets. More sophisticated inventories methodologies for at least key emission source are needed due to policy-driven air quality directives. Quantifying land cover changes on an annual basis requires greater spatial and temporal disaggregation of input data. The main aim of this study is to develop a methodology for using Earth Observations (EO) to identify annual land surface changes that will improve emissions inventories from agriculture and land use/land use change and forestry (LULUCF) in the UK. First goal is to find the best sets of input features that describe accurately the surface dynamics. In order to identify annual and inter-annual land surface changes, a times series of surface reflectance was used to capture seasonal variability. Daily surface reflectance images from the Moderate Resolution Imaging Spectroradiometer (MODIS) at 500m resolution were used to invert a Bidirectional Reflectance Distribution Function (BRDF) model to create the seamless time series. Given the limited number of cloud-free observations, a BRDF climatology was used to constrain the model inversion and where no high-scientific quality observations were available at all, as a gap filler. The Land Cover Map 2007 (LC2007) produced by the Centre for Ecology & Hydrology (CEH) was used for training and testing purposes. A prototype land cover product was created for 2006 to 2008. Several machine learning classifiers were tested as well as different sets of input features going from the BRDF parameters to spectral Albedo. We will present the results of the time series development and the first exercises when creating the prototype land cover product.

  18. Dynamic Inversion of Global Surface Microwave Emissivity Using a 1DVAR Approach

    Directory of Open Access Journals (Sweden)

    Sid-Ahmed Boukabara

    2018-04-01

    Full Text Available A variational inversion scheme is used to extract microwave emissivity spectra from brightness temperatures over a multitude of surface types. The scheme is called the Microwave Integrated Retrieval System and has been implemented operationally since 2007 at NOAA. This study focuses on the Advance Microwave Sounding Unit (AMSU/MHS pair onboard the NOAA-18 platform, but the algorithm is applied routinely to multiple microwave sensors, including the Advanced Technology Microwave Sounder (ATMS on Suomi-National Polar-orbiting Partnership (SNPP, Special Sensor Microwave Imager/Sounder (SSMI/S on the Defense Meteorological Satellite Program (DMSP flight units, as well as to the Global Precipitation Mission (GPM Microwave Imager (GMI, to name a few. The emissivity spectrum retrieval is entirely based on a physical approach. To optimize the use of information content from the measurements, the emissivity is extracted simultaneously with other parameters impacting the measurements, namely, the vertical profiles of temperature, moisture and cloud, as well as the skin temperature and hydrometeor parameters when rain or ice are present. The final solution is therefore a consistent set of parameters that fit the measured brightness temperatures within the instrument noise level. No ancillary data are needed to perform this dynamic emissivity inversion. By allowing the emissivity to be part of the retrieved state vector, it becomes easy to handle the pixel-to-pixel variation in the emissivity over non-oceanic surfaces. This is particularly important in highly variable surface backgrounds. The retrieved emissivity spectrum by itself is of value (as a wetness index for instance, but it is also post-processed to determine surface geophysical parameters. Among the parameters retrieved from the emissivity using this approach are snow cover, snow water equivalent and effective grain size over snow-covered surfaces, sea-ice concentration and age from ice-covered

  19. Perceiving a Calling, Living a Calling, and Job Satisfaction: Testing a Moderated, Multiple Mediator Model

    Science.gov (United States)

    Duffy, Ryan D.; Bott, Elizabeth M.; Allan, Blake A.; Torrey, Carrie L.; Dik, Bryan J.

    2012-01-01

    The current study examined the relation between perceiving a calling, living a calling, and job satisfaction among a diverse group of employed adults who completed an online survey (N = 201). Perceiving a calling and living a calling were positively correlated with career commitment, work meaning, and job satisfaction. Living a calling moderated…

  20. Decontamination by replacing soil and soil cover with deep-level soil in flower beds and vacant places in Northern Fukushima Prefecture

    International Nuclear Information System (INIS)

    Sugiura, Hiroyuki; Kawano, Keisuke; Kayama, Yukihiko; Koube, Nobuyuki

    2012-01-01

    Radioactivity decontamination by replacing soil and soil cover with deep-level soil and soil cover in flower beds and a vacant place in Northern Fukushima Prefecture were studied, which experienced radioactive contamination due to the accident at the TEPCO's Fukushima Daiichi Nuclear Power Plant. Radioactivity counting rate 1 cm above the soil surface after replacing surface soil with uncontaminated deep-level soil decreased to 13.7% of the control in gardens. The concentration of radioactive cesium in the cover soil increased after 132 days; however, it decreased in the old surface soil under the cover soil in flower beds. A 10 cm deep-level soil cover placed by heavy machinery decreased the radiation dose rate to 70.8% of the control and radioactivity counting rate to 24.6% in the vacant place. Replacing the radioactively contaminated surface soil and soil cover with a deep-level soil was a reasonable decontamination method for the garden and vacant place because it is quick, cost effective and labour efficient. (author)

  1. Near-field investigation of surface plasmon polaritons

    NARCIS (Netherlands)

    Jose, J.

    2010-01-01

    The interaction of light with metals contains a resonant phenomenon called the Surface Plasmon Resonance (SPR), at which the free electrons in the metal collectively oscillate. This collective oscillation of the free electrons, called Surface Plasmon Polaritons (SPPs), is highly sensitive to the

  2. Development of a methodology for monthly forecasting of surface fires of Colombia's vegetation cover, an application to north Andean region

    International Nuclear Information System (INIS)

    Gonzalez Hernandez, Yolanda; Rangel CH, Jesus Orlando

    2004-01-01

    In the present article a methodology is presented for the forecasting of the monthly risk of surface fires of the vegetation cover in Colombia, based on the analysis of meteorological components and variables of climatic and anthropic variability involved in fire risks of the north Andean region. The methodology enables one to regionalize the country, with fire prediction purposes in mind, into ten sub-regions, in each one of which seven height levels are defined to make up separate regions of study. For each of these, a database is built to feed both the logistic regression models and the Poisson models, which identify the variables independent from, and/or associated with the presence or absence of fires

  3. Land Cover - Minnesota Land Cover Classification System

    Data.gov (United States)

    Minnesota Department of Natural Resources — Land cover data set based on the Minnesota Land Cover Classification System (MLCCS) coding scheme. This data was produced using a combination of aerial photograph...

  4. Rotational electrical impedance tomography using electrodes with limited surface coverage provides window for multimodal sensing

    Science.gov (United States)

    Lehti-Polojärvi, Mari; Koskela, Olli; Seppänen, Aku; Figueiras, Edite; Hyttinen, Jari

    2018-02-01

    Electrical impedance tomography (EIT) is an imaging method that could become a valuable tool in multimodal applications. One challenge in simultaneous multimodal imaging is that typically the EIT electrodes cover a large portion of the object surface. This paper investigates the feasibility of rotational EIT (rEIT) in applications where electrodes cover only a limited angle of the surface of the object. In the studied rEIT, the object is rotated a full 360° during a set of measurements to increase the information content of the data. We call this approach limited angle full revolution rEIT (LAFR-rEIT). We test LAFR-rEIT setups in two-dimensional geometries with computational and experimental data. We use up to 256 rotational measurement positions, which requires a new way to solve the forward and inverse problem of rEIT. For this, we provide a modification, available for EIDORS, in the supplementary material. The computational results demonstrate that LAFR-rEIT with eight electrodes produce the same image quality as conventional 16-electrode rEIT, when data from an adequate number of rotational measurement positions are used. Both computational and experimental results indicate that the novel LAFR-rEIT provides good EIT with setups with limited surface coverage and a small number of electrodes.

  5. Behavioral Preferences for Individual Securities : The Case for Call Warrants and Call Options

    NARCIS (Netherlands)

    Ter Horst, J.R.; Veld, C.H.

    2002-01-01

    Since 1998, large investment banks have flooded the European capital markets with issues of call warrants.This has led to a unique situation in the Netherlands, where now call warrants, traded on the stock exchange, and long-term call options, traded on the options exchange, exist.Both entitle their

  6. TESTING OF LAND COVER CLASSIFICATION FROM MULTISPECTRAL AIRBORNE LASER SCANNING DATA

    Directory of Open Access Journals (Sweden)

    K. Bakuła

    2016-06-01

    Full Text Available Multispectral Airborne Laser Scanning provides a new opportunity for airborne data collection. It provides high-density topographic surveying and is also a useful tool for land cover mapping. Use of a minimum of three intensity images from a multiwavelength laser scanner and 3D information included in the digital surface model has the potential for land cover/use classification and a discussion about the application of this type of data in land cover/use mapping has recently begun. In the test study, three laser reflectance intensity images (orthogonalized point cloud acquired in green, near-infrared and short-wave infrared bands, together with a digital surface model, were used in land cover/use classification where six classes were distinguished: water, sand and gravel, concrete and asphalt, low vegetation, trees and buildings. In the tested methods, different approaches for classification were applied: spectral (based only on laser reflectance intensity images, spectral with elevation data as additional input data, and spectro-textural, using morphological granulometry as a method of texture analysis of both types of data: spectral images and the digital surface model. The method of generating the intensity raster was also tested in the experiment. Reference data were created based on visual interpretation of ALS data and traditional optical aerial and satellite images. The results have shown that multispectral ALS data are unlike typical multispectral optical images, and they have a major potential for land cover/use classification. An overall accuracy of classification over 90% was achieved. The fusion of multi-wavelength laser intensity images and elevation data, with the additional use of textural information derived from granulometric analysis of images, helped to improve the accuracy of classification significantly. The method of interpolation for the intensity raster was not very helpful, and using intensity rasters with both first and

  7. Temporal Land Cover Analysis for Net Ecosystem Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Yinghai; Coleman, Andre M.; Diefenderfer, Heida L.

    2013-04-09

    We delineated 8 watersheds contributing to previously defined river reaches within the 1,468-km2 historical floodplain of the tidally influenced lower Columbia River and estuary. We assessed land-cover change at the watershed, reach, and restoration site scales by reclassifying remote-sensing data from the National Oceanic and Atmospheric Administration Coastal Change Analysis Program’s land cover/land change product into forest, wetland, and urban categories. The analysis showed a 198.3 km2 loss of forest cover during the first 6 years of the Columbia Estuary Ecosystem Restoration Program, 2001–2006. Total measured urbanization in the contributing watersheds of the estuary during the full 1996-2006 change analysis period was 48.4 km2. Trends in forest gain/loss and urbanization differed between watersheds. Wetland gains and losses were within the margin of error of the satellite imagery analysis. No significant land cover change was measured at restoration sites, although it was visible in aerial imagery, therefore, the 30-m land-cover product may not be appropriate for assessment of early-stage wetland restoration. These findings suggest that floodplain restoration sites in reaches downstream of watersheds with decreasing forest cover will be subject to increased sediment loads, and those downstream of urbanization will experience effects of increased impervious surfaces on hydrologic processes.

  8. Mapping land cover change over continental Africa using Landsat and Google Earth Engine cloud computing.

    Science.gov (United States)

    Midekisa, Alemayehu; Holl, Felix; Savory, David J; Andrade-Pacheco, Ricardo; Gething, Peter W; Bennett, Adam; Sturrock, Hugh J W

    2017-01-01

    Quantifying and monitoring the spatial and temporal dynamics of the global land cover is critical for better understanding many of the Earth's land surface processes. However, the lack of regularly updated, continental-scale, and high spatial resolution (30 m) land cover data limit our ability to better understand the spatial extent and the temporal dynamics of land surface changes. Despite the free availability of high spatial resolution Landsat satellite data, continental-scale land cover mapping using high resolution Landsat satellite data was not feasible until now due to the need for high-performance computing to store, process, and analyze this large volume of high resolution satellite data. In this study, we present an approach to quantify continental land cover and impervious surface changes over a long period of time (15 years) using high resolution Landsat satellite observations and Google Earth Engine cloud computing platform. The approach applied here to overcome the computational challenges of handling big earth observation data by using cloud computing can help scientists and practitioners who lack high-performance computational resources.

  9. Classification of Land Cover and Land Use Based on Convolutional Neural Networks

    Science.gov (United States)

    Yang, Chun; Rottensteiner, Franz; Heipke, Christian

    2018-04-01

    Land cover describes the physical material of the earth's surface, whereas land use describes the socio-economic function of a piece of land. Land use information is typically collected in geospatial databases. As such databases become outdated quickly, an automatic update process is required. This paper presents a new approach to determine land cover and to classify land use objects based on convolutional neural networks (CNN). The input data are aerial images and derived data such as digital surface models. Firstly, we apply a CNN to determine the land cover for each pixel of the input image. We compare different CNN structures, all of them based on an encoder-decoder structure for obtaining dense class predictions. Secondly, we propose a new CNN-based methodology for the prediction of the land use label of objects from a geospatial database. In this context, we present a strategy for generating image patches of identical size from the input data, which are classified by a CNN. Again, we compare different CNN architectures. Our experiments show that an overall accuracy of up to 85.7 % and 77.4 % can be achieved for land cover and land use, respectively. The classification of land cover has a positive contribution to the classification of the land use classification.

  10. Electromagnetic local density of states in graphene-covered porous silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ting [Department of Physics, Nanchang University, Nanchang 330031 (China); Wang, Tong-Biao, E-mail: tbwang@ncu.edu.cn [Department of Physics, Nanchang University, Nanchang 330031 (China); Liao, Qing-Hua; Liu, Jiang-Tao; Yu, Tian-Bao [Department of Physics, Nanchang University, Nanchang 330031 (China); Liu, Nian-Hua [Institute for Advanced Study, Nanchang University, Nanchang 330031 (China)

    2017-06-21

    Surface phonon polariton supported by silicon carbide (SiC) can be strongly coupled with graphene plasmon in the graphene-covered SiC bulk. The spectrum of the electromagnetic local density of states exhibits two peaks whose positions can be tuned by the chemical potential of graphene. In this work, we study the electromagnetic local density of states in the proximity of a graphene-covered SiC with periodic hole arrays. The well-known peak from the coupling of surface polariton supported by SiC and graphene plasmon splits into two. With increased volume ratio of holes, one of the split peak shifts towards high frequencies, whereas the other moves towards low frequencies. The dependence of split-peak positions on the chemical potential and permittivity of filling materials in the holes are also investigated. This study offers another method of modulating the electromagnetic local density of states. - Highlights: • The electromagnetic local density of states in the proximity of graphene-covered anisotropic SiC is firstly studied. • The peak from resonance of surface phonon polaritons in the EM-LDOS spectrum can be split into two. • The split peaks can be tuned by chemical potential, filling factor, and filling materials. • Our results provide a new method to modulate the EM-LDOS.

  11. Simulated impacts of land cover change on summer climate in the Tibetan Plateau

    International Nuclear Information System (INIS)

    Li Qian; Xue Yongkang

    2010-01-01

    The Tibetan Plateau (TP) is a key region of land-atmosphere interactions with severe eco-environment degradation. This study uses an atmospheric general circulation model, NCEP GCM/SSiB, to present the major TP summer climate features for six selected ENSO years and preliminarily assess the possible impact of land cover change on the summer circulation over the TP. Compared to Reanalysis II data, the GCM using satellite derived vegetation properties generally reproduces the main 6-year-mean TP summer circulation features despite some discrepancies in intensity and geographic locations of some climate features. Two existing vegetation maps with very different land cover conditions over the TP, one with bare ground and one with vegetation cover, derived from satellite derived data, are tested and produce clearer climate signals due to land cover change. It shows that land cover change from vegetated land to bare ground decreases the radiation absorbed by the surface and results in weaker surface thermal effects, which lead to lower atmospheric temperature, as well as weaker vertical ascending motion, low-layer cyclonic, upper level anticyclonic, and summer monsoon circulation. These changes in circulation cause a decrease in the precipitation in the southeastern TP.

  12. Measurement of ion species produced due to bombardment of 450 eV N{sub 2}{sup +} ions with hydrocarbons-covered surface of tungsten: Formation of tungsten nitride

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. [Atomic Physics Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005 (India); Bhatt, P. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Kumar, A. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India); Singh, B.K.; Singh, B.; Prajapati, S. [Atomic Physics Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005 (India); Shanker, R., E-mail: shankerorama@gmail.com [Atomic Physics Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005 (India)

    2016-08-01

    A laboratory experiment has been performed to study the ions that are produced due to collisions of 450 eV N{sub 2}{sup +} ions with a hydrocarbons-covered surface of polycrystalline tungsten at room temperature. Using a TOF mass spectrometry technique, the product ions formed in these collisions have been detected, identified and analyzed. Different ion–surface reaction processes, namely, neutralization, reflection, surface induced dissociation, surface induced chemical reactions and desorption are observed and discussed. Apart from the presence of desorbed aliphatic hydrocarbon and other ions, the mass spectra obtained from the considered collisions show the formation and sputtering of tungsten nitride (WN). A layer of WN on tungsten surface is known to decrease the sputtering of bulk tungsten in fusion devices more effectively than when the tungsten is bombarded with other seeding gases (He, Ar). It is further noted that there is a negligible diffusion of N in the bulk tungsten at room temperature.

  13. Supraglacial Ponds Regulate Runoff From Himalayan Debris-Covered Glaciers

    Science.gov (United States)

    Irvine-Fynn, Tristram D. L.; Porter, Philip R.; Rowan, Ann V.; Quincey, Duncan J.; Gibson, Morgan J.; Bridge, Jonathan W.; Watson, C. Scott; Hubbard, Alun; Glasser, Neil F.

    2017-12-01

    Meltwater and runoff from glaciers in High Mountain Asia is a vital freshwater resource for one-fifth of the Earth's population. Between 13% and 36% of the region's glacierized areas exhibit surface debris cover and associated supraglacial ponds whose hydrological buffering roles remain unconstrained. We present a high-resolution meltwater hydrograph from the extensively debris-covered Khumbu Glacier, Nepal, spanning a 7 month period in 2014. Supraglacial ponds and accompanying debris cover modulate proglacial discharge by acting as transient and evolving reservoirs. Diurnally, the supraglacial pond system may store >23% of observed mean daily discharge, with mean recession constants ranging from 31 to 108 h. Given projections of increased debris cover and supraglacial pond extent across High Mountain Asia, we conclude that runoff regimes may become progressively buffered by the presence of supraglacial reservoirs. Incorporation of these processes is critical to improve predictions of the region's freshwater resource availability and cascading environmental effects downstream.

  14. Metrology and properties of engineering surfaces

    CERN Document Server

    Greenwood, J; Chetwynd, D

    2001-01-01

    Metrology and Properties of Engineering Surfaces provides in a single volume a comprehensive and authoritative treatment of the crucial topics involved in the metrology and properties of engineering surfaces. The subject matter is a central issue in manufacturing technology, since the quality and reliability of manufactured components depend greatly upon the selection and qualities of the appropriate materials as ascertained through measurement. The book can in broad terms be split into two parts; the first deals with the metrology of engineering surfaces and covers the important issues relating to the measurement and characterization of surfaces in both two and three dimensions. This covers topics such as filtering, power spectral densities, autocorrelation functions and the use of Fractals in topography. A significant proportion is dedicated to the calibration of scanning probe microscopes using the latest techniques. The remainder of the book deals with the properties of engineering surfaces and covers a w...

  15. A Combined Approach to Classifying Land Surface Cover of Urban Domestic Gardens Using Citizen Science Data and High Resolution Image Analysis

    Directory of Open Access Journals (Sweden)

    Fraser Baker

    2018-03-01

    Full Text Available Domestic gardens are an important component of cities, contributing significantly to urban green infrastructure (GI and its associated ecosystem services. However, domestic gardens are incredibly heterogeneous which presents challenges for quantifying their GI contribution and associated benefits for sustainable urban development. This study applies an innovative methodology that combines citizen science data with high resolution image analysis to create a garden dataset in the case study city of Manchester, UK. An online Citizen Science Survey (CSS collected estimates of proportional coverage for 10 garden land surface types from 1031 city residents. High resolution image analysis was conducted to validate the CSS estimates, and to classify 7 land surface cover categories for all garden parcels in the city. Validation of the CSS land surface estimations revealed a mean accuracy of 76.63% (s = 15.24%, demonstrating that citizens are able to provide valid estimates of garden surface coverage proportions. An Object Based Image Analysis (OBIA classification achieved an estimated overall accuracy of 82%, with further processing required to classify shadow objects. CSS land surface estimations were then extrapolated across the entire classification through calculation of within image class proportions, to provide the proportional coverage of 10 garden land surface types (buildings, hard impervious surfaces, hard pervious surfaces, bare soil, trees, shrubs, mown grass, rough grass, cultivated land, water within every garden parcel in the city. The final dataset provides a better understanding of the composition of GI in domestic gardens and how this varies across the city. An average garden in Manchester has 50.23% GI, including trees (16.54%, mown grass (14.46%, shrubs (9.19%, cultivated land (7.62%, rough grass (1.97% and water (0.45%. At the city scale, Manchester has 49.0% GI, and around one fifth (20.94% of this GI is contained within domestic

  16. CORINE Land Cover 2000 (IandCLC2000)

    International Nuclear Information System (INIS)

    Novacek, J.

    2005-01-01

    Remote Sensing for the Earth is one of the method for obtaining of information about objects of the Earth surface. Satellite snapshots were basic source of information for this project. Slovak Environmental Agency was the coordinator of this project to the Slovak Republic and co-research organisation was Geographic Institute, Slovak Academy of Sciences. Interpretation of satellite snapshots enabled to obtain information about position and area of natural ranges of 44 classes of landscape cover of Europe, from which in the Slovakia occurs 31 classes. Resulting thematic layers of landscape cover of the Slovakia during the years 1990 and 2000 are significant for analysis of trends, reasons and implications of nature and social processes which proceeds in the time and place of given territory

  17. Snow cover distribution over elevation zones in a mountainous catchment

    Science.gov (United States)

    Panagoulia, D.; Panagopoulos, Y.

    2009-04-01

    A good understanding of the elevetional distribution of snow cover is necessary to predict the timing and volume of runoff. In a complex mountainous terrain the snow cover distribution within a watershed is highly variable in time and space and is dependent on elevation, slope, aspect, vegetation type, surface roughness, radiation load, and energy exchange at the snow-air interface. Decreases in snowpack due to climate change could disrupt the downstream urban and agricultural water supplies, while increases could lead to seasonal flooding. Solar and longwave radiation are dominant energy inputs driving the ablation process. Turbulent energy exchange at the snow cover surface is important during the snow season. The evaporation of blowing and drifting snow is strongly dependent upon wind speed. Much of the spatial heterogeneity of snow cover is the result of snow redistribution by wind. Elevation is important in determining temperature and precipitation gradients along hillslopes, while the temperature gradients determine where precipitation falls as rain and snow and contribute to variable melt rates within the hillslope. Under these premises, the snow accumulation and ablation (SAA) model of the US National Weather Service (US NWS) was applied to implement the snow cover extent over elevation zones of a mountainous catchment (the Mesochora catchment in Western-Central Greece), taking also into account the indirectly included processes of sublimation, interception, and snow redistribution. The catchment hydrology is controlled by snowfall and snowmelt and the simulated discharge was computed from the soil moisture accounting (SMA) model of the US NWS and compared to the measured discharge. The elevationally distributed snow cover extent presented different patterns with different time of maximization, extinction and return during the year, producing different timing of discharge that is a crucial factor for the control and management of water resources systems.

  18. Control of water infiltration into near-surface, low-level waste-disposal units in humid regions

    International Nuclear Information System (INIS)

    O'Donnell, E.; Ridky, R.W.; Schulz, R.K.

    1994-01-01

    This study's objective is to assess means for controlling water infiltration through waste-disposal unit covers in humid regions. Experimental work is being performed in large-scale lysimeters (75 ft x 45 ft x 10 ft) at Beltsville, Maryland. Results of the assessment are applicable to disposal of low-level radioactive waste (LLW), uranium mill tailings, hazardous waste, and sanitary landfills. Three kinds of waste-disposal unit covers or barriers to water infiltration are being investigated: (1) resistive layer barrier, (2) conductive layer barrier, and (3) bioengineering management. The resistive layer barrier consists of compacted earthen material (e.g., clay). The conductive layer barrier consists of a conductive layer in conjunction with a capillary break. As long as unsaturated flow conditions are maintained, the conductive layer will wick water around the capillary break. Below-grade layered covers such as (1) and (2) will fail if there is appreciable subsidence of the cover, and remedial action for this kind of failure will be difficult. A surface cover, called bioengineering management, is meant to overcome this problem. The bioengineering management surface barrier is easily repairable if damaged by subsidence; therefore, it could be the system of choice under active subsidence conditions. The bioengineering management procedure also has been shown to be effective in dewatering saturated trenches and could be used for remedial action efforts. After cessation of subsidence, that procedure could be replaced by a resistive layer barrier or, perhaps even better, by a resistive layer barrier/conductive layer barrier system. The latter system would then give long-term effective protection against water entry into waste without institutional care

  19. Terrorism cover in France for property damage including nuclear risks

    International Nuclear Information System (INIS)

    Stanislas, A.

    2004-01-01

    The obligation to include terrorism cover in all Property Damage policies issued on the French Market is ruled by an Act of 1986 and introduced under Section R 126-2 of the French Code of Insurance. This section stipulates that Property Damage policies must provide cover for damage resulting from acts of terrorism, with the same deductible and the same limit than that of the other damage covered in the policy. Soon after the dramatic events of September 11, 2001 in the United States and although reinsurers worldwide restricted their offer of capacities, French insurers recognized that they had to maintain this global cover for the benefit of their insurers. After difficult discussions between insurers, reinsurers, brokers, risk managers and representatives of the State, the creation of a new Pool, backed with a State guarantee, was decided in less than three months. Effective January 1, 2002 and called Gestion d'Assurance et de Reassurance des Risques Attentats et Actes de Terrorisme (GAREAT), the Pool offers a multiple layers stop-loss cover for Property Damage only, i.e. excluding TPL policies. Considering that nuclear risks should be treated in the same way as other industrial risks, it was decided that they would be covered by GAREAT as well. In the meantime, by a Decree of December 28, 2001 modifying Section R 126-2, a special provision, aiming at reducing the limit and thus the price of this cover, was introduced in the Code. The purpose of this paper is to expose the present situation applying through GAREAT and, after two years of operation to discuss future developments, including other sources of capacity for the coverage of acts of terrorism in nuclear risks insurance.(author)

  20. Urban Soil: Assessing Ground Cover Impact on Surface Temperature and Thermal Comfort.

    Science.gov (United States)

    Brandani, Giada; Napoli, Marco; Massetti, Luciano; Petralli, Martina; Orlandini, Simone

    2016-01-01

    The urban population growth, together with the contemporary deindustrialization of metropolitan areas, has resulted in a large amount of available land with new possible uses. It is well known that urban green areas provide several benefits in the surrounding environment, such as the improvement of thermal comfort conditions for the population during summer heat waves. The purpose of this study is to provide useful information on thermal regimes of urban soils to urban planners to be used during an urban transformation to mitigate surface temperatures and improve human thermal comfort. Field measurements of solar radiation, surface temperature (), air temperature (), relative humidity, and wind speed were collected on four types of urban soils and pavements in the city of Florence during summer 2014. Analysis of days under calm, clear-sky condition is reported. During daytime, sun-to-shadow differences for , apparent temperature index (ATI), and were significantly positive for all surfaces. Conversely, during nighttime, differences among all surfaces were significantly negative, whereas ATI showed significantly positive differences. Moreover, was significantly negative for grass and gravel. Relative to the shaded surfaces, was higher on white gravel and grass than gray sandstone and asphalt during nighttime, whereas gray sandstone was always the warmest surface during daytime. Conversely, no differences were found during nighttime for ATI and measured over surfaces that were exposed to sun during the day, whereas showed higher values on gravel than grass and asphalt during nighttime. An exposed surface warms less if its albedo is high, leading to a significant reduction of during daytime. These results underline the importance of considering the effects of surface characteristics on surface temperature and thermal comfort. This would be fundamental for addressing urban environment issues toward the heat island mitigation considering also the impact of urban

  1. Land cover mapping of Greater Mesoamerica using MODIS data

    Science.gov (United States)

    Giri, Chandra; Jenkins, Clinton N.

    2005-01-01

    A new land cover database of Greater Mesoamerica has been prepared using moderate resolution imaging spectroradiometer (MODIS, 500 m resolution) satellite data. Daily surface reflectance MODIS data and a suite of ancillary data were used in preparing the database by employing a decision tree classification approach. The new land cover data are an improvement over traditional advanced very high resolution radiometer (AVHRR) based land cover data in terms of both spatial and thematic details. The dominant land cover type in Greater Mesoamerica is forest (39%), followed by shrubland (30%) and cropland (22%). Country analysis shows forest as the dominant land cover type in Belize (62%), Cost Rica (52%), Guatemala (53%), Honduras (56%), Nicaragua (53%), and Panama (48%), cropland as the dominant land cover type in El Salvador (60.5%), and shrubland as the dominant land cover type in Mexico (37%). A three-step approach was used to assess the quality of the classified land cover data: (i) qualitative assessment provided good insight in identifying and correcting gross errors; (ii) correlation analysis of MODIS- and Landsat-derived land cover data revealed strong positive association for forest (r2 = 0.88), shrubland (r2 = 0.75), and cropland (r2 = 0.97) but weak positive association for grassland (r2 = 0.26); and (iii) an error matrix generated using unseen training data provided an overall accuracy of 77.3% with a Kappa coefficient of 0.73608. Overall, MODIS 500 m data and the methodology used were found to be quite useful for broad-scale land cover mapping of Greater Mesoamerica.

  2. Physician alert: the legal risks associated with 'on-call' duties in the USA.

    Science.gov (United States)

    Paterick, Zachary R; Patel, Nachiket J; Paterick, Timothy Edward

    2018-06-13

    On-call physicians encounter a diverse aggregate of interfaces with sundry persons concerning patient care that may surface potential legal peril. The duties and obligations of an on-call physician, who must act as a fiduciary to all patients, create a myriad of circumstances where there is a risk of falling prey to legal ambiguities. The understanding of the doctor-patient relationship, the obligations of physicians under the Emergency Medical Treatment and Labor Act, the meaning of medical informed consent and the elements of negligence will help physicians avoid the legal risk associated with the various encounters of being on call. After introducing the legal concepts, we will explore the interactions that may put physicians at legal risk and outline how to mitigate that risk. Being on call is time consuming and arduous. While on call, physicians have a duty to act morally and ethically in the best interest of the patients. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  3. Permafrost thaw and fire history: implications of boreal tree cover changes on land surface properties and turbulent energy fluxes in the Taiga Plains, Canada

    Science.gov (United States)

    Sonnentag, Oliver; Helbig, Manuel; Payette, Fanny; Wischnewski, Karoline; Kljun, Natascha; Chasmer, Laura; Pappas, Christoforos; Detto, Matteo; Baltzer, Jennifer; Quinton, William; Marsh, Philip

    2016-04-01

    Given their large areal coverage, high carbon densities, and unique land surface properties and disturbance regimes (e.g., wildfires), the world's boreal forests are integral components of the global and regional climate systems. A large portion of boreal forests contain permafrost, i.e., perennially cryotic ground. In the Taiga Plains ecozone in northwestern Canada, the northernmost boreal forests grow on cold (100 m) continuous permafrost (>90 % in areal extent). More southerly boreal forests occur in areas with discontinuous (>50 - 90 % in areal extent), sporadic (>10 - 50 % in areal extent) and isolated permafrost (<10 % in areal extent). Using annual MODIS Percent Tree Cover (PTC) data from the MOD44B product in combination with spatial information on fire history, and permafrost and drainage characteristics, we show that in low-lying, poorly-drained areas along the southern fringe of permafrost, thawing induces widespread decreases in PTC and dominates over PTC increases due to post-fire regrowth. In contrast, PTC appears to be slightly increasing in the central and northern Taiga Plains with more stable discontinuous and continuous permafrost, respectively. While these increases are partly explained by post-fire regrowth, more favourable growing conditions may also contribute to increasing PTC. To better understand the implications of permafrost thaw on land surface properties (e.g., aerodynamic conductance for heat [ga] and surface conductance for water vapour [gs]), and the turbulent fluxes of latent (LE) and sensible heat (H) along the southern fringe of permafrost, we examined nested eddy covariance flux measurements made at two nearby locations at Scotty Creek (61°18' N; 121°18' W) starting May 2013. The low-lying, poorly-drained southern portion of this 152 km2-watershed contains rapidly thawing sporadic permafrost resulting in a highly dynamic mosaic dominated by decreasing forested permafrost peat plateaus, and increasing permafrost-free wetlands

  4. Evaporation suppression from water reservoirs using floating covers: Lab scale observations and model predictions

    Science.gov (United States)

    Or, D.; Lehmann, P.; Aminzadeh, M.; Sommer, M.; Wey, H.; Wunderli, H.; Breitenstein, D.

    2016-12-01

    The competition over dwindling fresh water resources is expected to intensify with projected increase in human population in arid regions, expansion of irrigated land and changes in climate and drought patterns. The volume of water stored in reservoirs would also increase to mitigate seasonal shortages due to rainfall variability and to meet irrigation water needs. By some estimates up to half of the stored water is lost to evaporation thereby exacerbating the water scarcity problem. Recently, there is an upsurge in the use of self-assembling floating covers to suppress evaporation, yet the design, and implementation remain largely empirical. Studies have shown that evaporation suppression is highly nonlinear, as also known from a century of research on gas exchange from plant leaves (that often evaporate as free water surfaces through stomata that are only 1% of leaf area). We report a systematic evaluation of different cover types and external drivers (radiation, wind, wind+radiation) on evaporation suppression and energy balance of a 1.4 m2 basin placed in a wind-tunnel. Surprisingly, evaporation suppression by black and white floating covers (balls and plates) were similar despite significantly different energy balance regimes over the cover surfaces. Moreover, the evaporation suppression efficiency was a simple function of the uncovered area (square root of the uncovered fraction) with linear relations with the covered area in some cases. The thermally decoupled floating covers offer an efficient solution to the evaporation suppression with limited influence of the surface energy balance (water temperature for black and white covers was similar and remained nearly constant). The results will be linked with a predictive evaporation-energy balance model and issues of spatial scales and long exposure times will be studied.

  5. Land-cover change research at the U.S. Geological Survey-assessing our nation's dynamic land surface

    Science.gov (United States)

    Wilson, Tamara S.

    2011-01-01

    The U.S. Geological Survey (USGS) recently completed an unprecedented, 27-year assessment of land-use and land-cover change for the conterminous United States. For the period 1973 to 2000, scientists generated estimates of change in major types of land use and land cover, such as development, mining, agriculture, forest, grasslands, and wetlands. To help provide the insight that our Nation will need to make land-use decisions in coming decades, the historical trends data is now being used by the USGS to help model potential future land use/land cover under different scenarios, including climate, environmental, economic, population, public policy, and technological change.

  6. Springtime warming and reduced snow cover from carbonaceous particles

    Directory of Open Access Journals (Sweden)

    M. G. Flanner

    2009-04-01

    Full Text Available Boreal spring climate is uniquely susceptible to solar warming mechanisms because it has expansive snow cover and receives relatively strong insolation. Carbonaceous particles can influence snow coverage by warming the atmosphere, reducing surface-incident solar energy (dimming, and reducing snow reflectance after deposition (darkening. We apply a range of models and observations to explore impacts of these processes on springtime climate, drawing several conclusions: 1 Nearly all atmospheric particles (those with visible-band single-scatter albedo less than 0.999, including all mixtures of black carbon (BC and organic matter (OM, increase net solar heating of the atmosphere-snow column. 2 Darkening caused by small concentrations of particles within snow exceeds the loss of absorbed energy from concurrent dimming, thus increasing solar heating of snowpack as well (positive net surface forcing. Over global snow, we estimate 6-fold greater surface forcing from darkening than dimming, caused by BC+OM. 3 Equilibrium climate experiments suggest that fossil fuel and biofuel emissions of BC+OM induce 95% as much springtime snow cover loss over Eurasia as anthropogenic carbon dioxide, a consequence of strong snow-albedo feedback and large BC+OM emissions from Asia. 4 Of 22 climate models contributing to the IPCC Fourth Assessment Report, 21 underpredict the rapid warming (0.64°C decade−1 observed over springtime Eurasia since 1979. Darkening from natural and anthropogenic sources of BC and mineral dust exerts 3-fold greater forcing on springtime snow over Eurasia (3.9 W m−2 than North America (1.2 W m−2. Inclusion of this forcing significantly improves simulated continental warming trends, but does not reconcile the low bias in rate of Eurasian spring snow cover decline exhibited by all models, likely because BC deposition trends are negative or near-neutral over much of Eurasia. Improved Eurasian

  7. The surface chemistry of metal-oxygen interactions

    DEFF Research Database (Denmark)

    Stokbro, Kurt; Baroni, Stefano

    1997-01-01

    We report on a computational study of the clean and oxygen-covered Rh(110) surface, based on density-functional theory within the local-density approximation. We have used plane-wave basis sets and Vanderbilt ultra-soft pseudopotentials. For the clean surface, we present results for the equilibrium...... structure, surface energy and surface stress of the unreconstructed and (1 x 2) reconstructed structures. For the oxygen-covered surface we have performed a geometry optimization at 0.5, 1, and 2 monolayer oxygen coverages, and we present results for the equilibrium configurations, workfunctions and oxygen...

  8. Topology optimization of an electronics cover plate with respect to eigenfrequencies

    DEFF Research Database (Denmark)

    A. Kristensen, Anders Schmidt

    In the present paper it is illustrated how topology optimization with respect to eigenfrequency can be applied effectively in the product development process. The topology optimization code is implemented in ANSYS by a so called UPF. The maximization of eigenfrequency as objective is invoked...... into the existing code. As an example is chosen an electronics cover plate. The resulting design devised by the topology optimization yield a significant higher eigenfrequency than obtained by traditional design methods and experience....

  9. Call Centre- Computer Telephone Integration

    Directory of Open Access Journals (Sweden)

    Dražen Kovačević

    2012-10-01

    Full Text Available Call centre largely came into being as a result of consumerneeds converging with enabling technology- and by the companiesrecognising the revenue opportunities generated by meetingthose needs thereby increasing customer satisfaction. Regardlessof the specific application or activity of a Call centre, customersatisfaction with the interaction is critical to the revenuegenerated or protected by the Call centre. Physical(v, Call centreset up is a place that includes computer, telephone and supervisorstation. Call centre can be available 24 hours a day - whenthe customer wants to make a purchase, needs information, orsimply wishes to register a complaint.

  10. Do Surface Energy Fluxes Reveal Land Use/Land Cover Change in South Florida?: A Remote Sensing Perspective

    Science.gov (United States)

    Kandel, H. P.; Melesse, A. M.

    2017-12-01

    Series of changes on land use/ land cover in South Florida resulting from drainage and development activities during early to mid-20th followed by restoration measures since late-20th century have had prominent impacts on hydrologic regime and energy fluxes in the region. Previous results from numerical modeling and MODIS-based analysis have shown a shift in dominance of heat fluxes: from latent to sensible along the axes of urbanization, and an opposite along the axes of restoration. This study implements a slightly modified version of surface energy balance algorithm (SEBAL) on cloud-masked Landsat imageries archived over the period of 30-years combined with ground-meteorological data for South Florida using spatial analysis model in ArcGIS and calculates energy flux components: sensible heat flux, latent heat flux, and ground heat flux. The study finally computes variation of Bowen's ratio (BR) and daily evapotranspiration (ET) rate over various land covers for different years. Coexistences are apparent between increased BR and increased intensity of urbanization, and between increased daily ET rates and improved best management practices in agricultural areas. An increase in mean urban BR from 1.67 in 1984 to 3.06 in 2010 show plausible link of BR with urban encroachment of open lands, and expulsion of additional heat by increased population/automobiles/factories/air conditioning units. Likewise, increase in mean agricultural daily ET rates from 0.21 mm/day to 3.60 mm/day between 1984 to 2010 probably shows the effects of improved moisture conditions on the northern farm lands as the results of restoration practices. Once new observed data become available to corroborate these results, remote sensing methods-owing to their greater spatial and temporal details-can be used as assessment measures both for the progress of restoration evaluation and for the extent detection of human-induced climate change.

  11. Clearance of buildings for demolition: ways to clearance on the standing structure for covered surfaces and inaccessible areas

    International Nuclear Information System (INIS)

    Thraenert, S.; Riemann, T.

    2014-01-01

    structure for about half of this area, and until 2014 most of the remaining area will be treated accordingly. However, due to the building design of Wuergassen NPP, not all surfaces are directly accessible to full-area characterization on the standing structure and not all areas can be completely decontaminated in a cost-effective manner. The most prominent structure is the open gap between the turbine foundations and the surrounding turbine building, but similar gaps also exist between the turbine building and, e.g., the reactor building. In addition, the lower basement floors of the RCA buildings consist of several horizontal layers of concrete which, during construction, did not completely bond. As a result, contaminated liquids propagated along the existing boundary surfaces and hot spots up to 100 kBq are now covered by about 0.5 m of low-activity material. For this variety of challenging examples Wuergassen NPP proposed the release process to the competent authority, performed measurements and provided interpretation of the data. The release process is aimed at verifying compliance with the clearance levels on the standing structure. TUV NORD Nuclear is involved in the release process on behalf of the competent authority to expertise the procedure, to supervise the measurements and to review the data evaluation. Regarding the boundary surfaces between two concrete layers it was possible to gain access to the covered surface by fragmenting the upper concrete layer into blocks. The decontaminated surfaces comply with the clearance levels and the decontaminated concrete blocks may remain on site. An existing gap between the turbine building and the reactor building was characterized by using special equipment. It could be shown, that the residual contamination within the gap complies with the clearance levels. If it is not possible to do a complete decontamination according to static reasons, the residual radioactivity can be determined for further use in the dose

  12. National Land Cover Database (NLCD) Land Cover Collection

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The National Land Cover Database (NLCD) Land Cover Collection is produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC)...

  13. Using Unmanned Aerial Vehicles to Assess Vegetative Cover in Sagebrush Steppe Ecosytstems

    Energy Technology Data Exchange (ETDEWEB)

    Robert P. Breckenridge

    2005-09-01

    The Idaho National Laboratory (INL), in conjunction with the University of Idaho, is evaluating novel approaches for using unmanned aerial vehicles (UAVs) as a quicker and safer method for monitoring biotic resources. Evaluating vegetative cover is an important factor in understanding the sustainability of many ecosystems. In assessing vegetative cover, methods that improve accuracy and cost efficiency could revolutionize how biotic resources are monitored on western federal lands. Sagebrush steppe ecosystems provide important habitat for a variety of species, some of which are important indicator species (e.g., sage grouse). Improved methods are needed to support monitoring these habitats because there are not enough resource specialists or funds available for comprehensive ground evaluation of these ecosystems. In this project, two types of UAV platforms (fixed wing and helicopter) were used to collect still-frame imagery to assess cover in sagebrush steppe ecosystems. This paper discusses the process for collecting and analyzing imagery from the UAVs to (1) estimate total percent cover, (2) estimate percent cover for six different types of vegetation, and (3) locate sage grouse based on representative decoys. The field plots were located on the INL site west of Idaho Falls, Idaho, in areas with varying amounts and types of vegetative cover. A software program called SamplePoint developed by the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS) was used to evaluate the imagery for percent cover for the six vegetation types (bare ground, litter, shrubs, dead shrubs, grasses, and forbs). Results were compared against standard field measurements to assess accuracy.

  14. Cloud cover detection combining high dynamic range sky images and ceilometer measurements

    Science.gov (United States)

    Román, R.; Cazorla, A.; Toledano, C.; Olmo, F. J.; Cachorro, V. E.; de Frutos, A.; Alados-Arboledas, L.

    2017-11-01

    This paper presents a new algorithm for cloud detection based on high dynamic range images from a sky camera and ceilometer measurements. The algorithm is also able to detect the obstruction of the sun. This algorithm, called CPC (Camera Plus Ceilometer), is based on the assumption that under cloud-free conditions the sky field must show symmetry. The symmetry criteria are applied depending on ceilometer measurements of the cloud base height. CPC algorithm is applied in two Spanish locations (Granada and Valladolid). The performance of CPC retrieving the sun conditions (obstructed or unobstructed) is analyzed in detail using as reference pyranometer measurements at Granada. CPC retrievals are in agreement with those derived from the reference pyranometer in 85% of the cases (it seems that this agreement does not depend on aerosol size or optical depth). The agreement percentage goes down to only 48% when another algorithm, based on Red-Blue Ratio (RBR), is applied to the sky camera images. The retrieved cloud cover at Granada and Valladolid is compared with that registered by trained meteorological observers. CPC cloud cover is in agreement with the reference showing a slight overestimation and a mean absolute error around 1 okta. A major advantage of the CPC algorithm with respect to the RBR method is that the determined cloud cover is independent of aerosol properties. The RBR algorithm overestimates cloud cover for coarse aerosols and high loads. Cloud cover obtained only from ceilometer shows similar results than CPC algorithm; but the horizontal distribution cannot be obtained. In addition, it has been observed that under quick and strong changes on cloud cover ceilometers retrieve a cloud cover fitting worse with the real cloud cover.

  15. T Tank Farm Interim Cover Test - Design Plan

    International Nuclear Information System (INIS)

    Zhang, Z. F.; Keller, Jason M.

    2006-01-01

    The Hanford Site has 149 underground single-shell tanks that store hazardous radioactive waste. Many of these tanks and their associated infrastructure (e.g., pipelines, diversion boxes) have leaked. Some of the leaked waste has entered the groundwater. The largest known leak occurred from the T-106 Tank in 1973. Many of the contaminants from that leak still reside within the vadose zone beneath the T Tank Farm. CH2M Hill Hanford Group, Inc. seeks to minimize movement of this residual contaminant plume by placing an interim cover on the surface. Such a cover is expected to prevent infiltrating water from reaching the plume and moving it further. Pacific Northwest National Laboratory has prepared a design plan to monitor and determine the effectiveness of the interim cover. A three-dimensional numerical simulation of water movement beneath a cover was conducted to guide the design of the plan. Soil water content, water pressure, and temperature will be monitored using off-the-shelf equipment that can be installed by the hydraulic hammer technique. In fiscal year 2006, two instrument nests will be installed, one inside and one outside of the proposed cover. In fiscal year 2007, two additional instrument nests, both inside the proposed cover, will be installed. Each instrument nest contains a neutron access tube and a capacitance probe (to measure water content), and four heat-dissipation units (to measure pressure head and temperature). A datalogger and a meteorological station will be installed outside of the fence. Two drain gauges will be installed in locations inside and outside the cover for the purpose of measuring soil water flux.

  16. Simulation of Forest Cover Dynamics for Eastern Eurasian Boreal Forests

    Science.gov (United States)

    Shugart, H. H.; Yan, X.; Zhang, N.; Isaev, A. S.; Shuman, J. K.

    2006-12-01

    We are developing and testing a boreal zone forest dynamics model capable of simulating the forest cover dynamics of the Eurasian boreal forest, a major biospheric ecosystem with potentially large roles in the planetary carbon cycle and in the feedback between terrestrial surface and the atmosphere. In appreciating the role of this region in the coupling between atmosphere and terrestrial surface, on must understand the interactions between CO2 source/sink relationships (associated with growing or clearing forests) and the albedo effects (from changes in terrestrial surface cover). There is some evidence that in the Eurasian Boreal zone, the Carbon budget effects from forest change may oppose the albedo changes. This creates complex feedbacks between surface and atmosphere and motivates the need for a forest dynamics model that simultaneous represents forest vegetation and carbon storage and release. A forest dynamics model applied to Eastern Eurasia, FAREAST, has been tested using three types of information: 1. Direct species composition comparisons between simulated and observed mature forests at the same locations; 2. Forest type comparisons between simulated and observed forests along altitudinal gradients of several different mountains; 3. Comparison with forest stands in different succession stages of simulated forests. Model comparisons with independent data indicate the FAREAST model is capable of representing many of the broad features of the forests of Northeastern China. After model validation in the Northeast China region, model applications were developed for the forests of the Russian Far East. Continental-scale forest cover can be simulated to a relatively realistic degree using a forest gap model with standard representations of individual-plant processes. It appears that such a model, validated relatively locally in this case, in Northeastern China, can then be applied over a much larger region and under conditions of climatic change.

  17. New course: “Lync – click to call and collaborate with others”

    CERN Multimedia

    2013-01-01

    The presentation will cover main features of Lync: initiating and receiving phone calls from Lync, chatting (Instant Message), how to stay connected as if you were in your office, creating and participating in online meetings, sharing presentations/desktops with other people, using voice mailbox on Exchange, integration with Outlook, CERN Phone book, phone system etc. General information about Lync can be found on http://cern.ch/lync. Softphone features of Lync are detailed on http://cern.ch/softphone. Next session: 16 May 2013 from 2 p.m. to 3 p.m. in English. Please register through the training catalogue. Lync service & Technical training

  18. Call cultures in orang-utans?

    Directory of Open Access Journals (Sweden)

    Serge A Wich

    Full Text Available BACKGROUND: Several studies suggested great ape cultures, arguing that human cumulative culture presumably evolved from such a foundation. These focused on conspicuous behaviours, and showed rich geographic variation, which could not be attributed to known ecological or genetic differences. Although geographic variation within call types (accents has previously been reported for orang-utans and other primate species, we examine geographic variation in the presence/absence of discrete call types (dialects. Because orang-utans have been shown to have geographic variation that is not completely explicable by genetic or ecological factors we hypothesized that this will be similar in the call domain and predict that discrete call type variation between populations will be found. METHODOLOGY/PRINCIPAL FINDINGS: We examined long-term behavioural data from five orang-utan populations and collected fecal samples for genetic analyses. We show that there is geographic variation in the presence of discrete types of calls. In exactly the same behavioural context (nest building and infant retrieval, individuals in different wild populations customarily emit either qualitatively different calls or calls in some but not in others. By comparing patterns in call-type and genetic similarity, we suggest that the observed variation is not likely to be explained by genetic or ecological differences. CONCLUSION/SIGNIFICANCE: These results are consistent with the potential presence of 'call cultures' and suggest that wild orang-utans possess the ability to invent arbitrary calls, which spread through social learning. These findings differ substantially from those that have been reported for primates before. First, the results reported here are on dialect and not on accent. Second, this study presents cases of production learning whereas most primate studies on vocal learning were cases of contextual learning. We conclude with speculating on how these findings might

  19. Surface Chemistry Dependence of Mechanochemical Reaction of Adsorbed Molecules-An Experimental Study on Tribopolymerization of α-Pinene on Metal, Metal Oxide, and Carbon Surfaces.

    Science.gov (United States)

    He, Xin; Kim, Seong H

    2018-02-20

    Mechanochemical reactions between adsorbate molecules sheared at tribological interfaces can induce association of adsorbed molecules, forming oligomeric and polymeric products often called tribopolymers). This study revealed the role or effect of surface chemistry of the solid substrate in mechanochemical polymerization reactions. As a model reactant, α-pinene was chosen because it was known to readily form tribopolymers at the sliding interface of stainless steel under vapor-phase lubrication conditions. Eight different substrate materials were tested-palladium, nickel, copper, stainless steel, gold, silicon oxide, aluminum oxide, and diamond-like carbon (DLC). All metal substrates and DLC were initially covered with surface oxide species formed naturally in air or during the oxidative sample cleaning. It was found that the tribopolymerization yield of α-pinene is much higher on the substrates that can chemisorb α-pinene, compared to the ones on which only physisorption occurs. From the load dependence of the tribopolymerization yield, it was found that the surfaces capable of chemisorption give a smaller critical activation volume for the mechanochemical reaction, compared to the ones capable of physisorption only. On the basis of these observations and infrared spectroscopy analyses of the adsorbed molecules and the produced polymers, it was concluded that the mechanochemical reaction mechanisms might be different between chemically reactive and inert surfaces and that the chemical reactivity of the substrate surface greatly influences the tribochemical polymerization reactions of adsorbed molecules.

  20. Effect of landslides on the structural characteristics of land-cover based on complex networks

    Science.gov (United States)

    He, Jing; Tang, Chuan; Liu, Gang; Li, Weile

    2017-09-01

    Landslides have been widely studied by geologists. However, previous studies mainly focused on the formation of landslides and never considered the effect of landslides on the structural characteristics of land-cover. Here we define the modeling of the graph topology for the land-cover, using the satellite images of the earth’s surface before and after the earthquake. We find that the land-cover network satisfies the power-law distribution, whether the land-cover contains landslides or not. However, landslides may change some parameters or measures of the structural characteristics of land-cover. The results show that the linear coefficient, modularity and area distribution are all changed after the occurence of landslides, which means the structural characteristics of the land-cover are changed.

  1. A Prognostic Methodology for Precipitation Phase Detection using GPM Microwave Observations —With Focus on Snow Cover

    Science.gov (United States)

    Takbiri, Z.; Ebtehaj, A.; Foufoula-Georgiou, E.; Kirstetter, P.

    2017-12-01

    Improving satellite retrieval of precipitation requires increased understanding of its passive microwave signature over different land surfaces. Passive microwave signals over snow-covered surfaces are notoriously difficult to interpret because they record both emission from the land below and absorption/scattering from the liquid/ice crystals. Using data from the Global Precipitation Measurement (GPM) core satellite, we demonstrate that the microwave brightness temperatures of rain and snowfall shifts from a scattering to an emission regime from summer to winter, due to expansion of the less emissive snow cover underneath. We present evidence that the combination of low- (10-19 GHz) and high-frequency (89-166 GHz) channels provides the maximum amount of information for snowfall detection. The study also examines a prognostic nearest neighbor matching method for the detection of precipitation and its phase from passive microwave observations using GPM data. The nearest neighbor uses the weighted Euclidean distance metric to search through an a priori database that is populated with coincident GPM radiometer and radar data as well as ancillary snow cover fraction. The results demonstrate prognostic capabilities of the proposed method in detection of terrestrial snowfall. At the global scale, the average probability of hit and false alarm reaches to 0.80 and remains below 0.10, respectively. Surprisingly, the results show that the snow cover may help to better detect precipitation as the detection rate of terrestrial precipitation is increased from 0.75 (no snow cover) to 0.84 (snow-covered surfaces). For solid precipitation, this increased rate of detection is larger than its liquid counterpart by almost 8%. The main reasons are found to be related to the multi-frequency capabilities of the nearest neighbor matching that can properly isolate the atmospheric signal from the background emission and the fact that the precipitation can exhibit an emission-like (warmer

  2. ASSESSING LAND COVER CHANGES CAUSED BY GRANITE QUARRYING USING REMOTE SENSING

    Directory of Open Access Journals (Sweden)

    R. S. Moeletsi

    2017-11-01

    Full Text Available Dimension stone quarrying in the area between Rustenburg and Brits in the North West Province of South Africa has been in existence for over 70 decades. The unique characteristics of the granite deposits in South Africa resulted in making the country a global producer of the granite rocks. This led to intensified quarrying activities between Rustenburg and Brits town. However, this surface mining method, has a potential to impact the environment in a negative way causing loss in vegetation, depletion of natural resources, loss of scenic beauty and contamination of surface water resources. To assess the land cover changes caused by granite quarrying activities, remotely sensed data in the form of Landsat images between 1998 and 2015 were used. Supervised classification was used to create maps. Accuracy assessment using Google EarthTM as a reference data yielded an overall accuracy of 78 %. The post classification change detection method was used to assess land cover changes within the granite quarries. Granite quarries increased by 1174.86 ha while formation of quarry lakes increased to 5.3 ha over the 17-year period. Vegetation cover decreased by 1308 ha in area while 18.3 ha bare land was lost during the same period. This study demonstrated the utility of remote sensing to detect changes in land cover within granite quarries.

  3. Cover technology demonstration for low-level radioactive sites

    International Nuclear Information System (INIS)

    Barnes, F.J.; Warren, J.L.

    1988-01-01

    The performance of a shallow land burial site in isolating low-level radioactive and mixed waste is strongly influenced by the behavior of the precipitation falling on the site. Predicting the long-term integrity of a cover design requires a knowledge of the water balance dynamics, and the use of predictive models. The multiplicity of factors operating on a site in the years post-closure (precipitation intensity and duration, soil conditions, vegetation seasonality and variability) have made it extremely difficult to predict the effects of natural precipitation with accuracy. Preliminary results are presented on a three-year field demonstration at Los Alamos National Laboratory to evaluate the influence of different waste trench cap designs on water balance under natural precipitation. Erosion plots having two different vegetative covers (shrubs and grasses) and with either gravel-mulched or unmulched soil surface treatments have been established on three different soil profiles on an inactive waste site. Total runoff and soil loss from each plot are measured biweekly while plant canopy cover is measured seasonally. Preliminary results from the first year show that the application of a gravel mulch reduced runoff by 73 to 90%. Total soil loss was reduced by 83 to 93% by the mulch treatment. On unmulched plots, grass cover reduced both runoff and soil loss by about 50% compared to the shrub plots. Soil moisture reduction during the growing season was more pronounced on the shrub plots. This indicates that a more complex vegetative cover provides greater soil moisture storage capacity for winter precipitation than the usual grass cover

  4. Hydrological response to land cover changes and human activities in arid regions using a geographic information system and remote sensing.

    Directory of Open Access Journals (Sweden)

    Shereif H Mahmoud

    Full Text Available The hydrological response to land cover changes induced by human activities in arid regions has attracted increased research interest in recent decades. The study reported herein assessed the spatial and quantitative changes in surface runoff resulting from land cover change in the Al-Baha region of Saudi Arabia between 1990 and 2000 using an ArcGIS-surface runoff model and predicted land cover and surface runoff depth in 2030 using Markov chain analysis. Land cover maps for 1990 and 2000 were derived from satellite images using ArcGIS 10.1. The findings reveal a 26% decrease in forest and shrubland area, 28% increase in irrigated cropland, 1.5% increase in sparsely vegetated land and 0.5% increase in bare soil between 1990 and 2000. Overall, land cover changes resulted in a significant decrease in runoff depth values in most of the region. The decrease in surface runoff depth ranged from 25-106 mm/year in a 7020-km2 area, whereas the increase in such depth reached only 10 mm/year in a 243-km2 area. A maximum increase of 73 mm/year was seen in a limited area. The surface runoff depth decreased to the greatest extent in the central region of the study area due to the huge transition in land cover classes associated with the construction of 25 rainwater harvesting dams. The land cover prediction revealed a greater than twofold increase in irrigated cropland during the 2000-2030 period, whereas forest and shrubland are anticipated to occupy just 225 km2 of land area by 2030, a significant decrease from the 747 km2 they occupied in 2000. Overall, changes in land cover are predicted to result in an annual increase in irrigated cropland and dramatic decline in forest area in the study area over the next few decades. The increase in surface runoff depth is likely to have significant implications for irrigation activities.

  5. The difficult medical emergency call

    DEFF Research Database (Denmark)

    Møller, Thea Palsgaard; Kjærulff, Thora Majlund; Viereck, Søren

    2017-01-01

    BACKGROUND: Pre-hospital emergency care requires proper categorization of emergency calls and assessment of emergency priority levels by the medical dispatchers. We investigated predictors for emergency call categorization as "unclear problem" in contrast to "symptom-specific" categories and the ......BACKGROUND: Pre-hospital emergency care requires proper categorization of emergency calls and assessment of emergency priority levels by the medical dispatchers. We investigated predictors for emergency call categorization as "unclear problem" in contrast to "symptom-specific" categories...... and the effect of categorization on mortality. METHODS: Register-based study in a 2-year period based on emergency call data from the emergency medical dispatch center in Copenhagen combined with nationwide register data. Logistic regression analysis (N = 78,040 individuals) was used for identification...

  6. BUSINESS MODELS FOR EXTENDING OF 112 EMERGENCY CALL CENTER CAPABILITIES WITH E-CALL FUNCTION INSERTION

    Directory of Open Access Journals (Sweden)

    Pop Dragos Paul

    2010-12-01

    Full Text Available The present article concerns present status of implementation in Romania and Europe of eCall service and the proposed business models regarding eCall function implementation in Romania. eCall system is used for reliable transmission in case of crush between In Vehicle System and Public Service Answering Point, via the voice channel of cellular and Public Switched Telephone Network (PSTN. eCall service could be initiated automatically or manual the driver. All data presented in this article are part of researches made by authors in the Sectorial Contract Implementation study regarding eCall system, having as partners ITS Romania and Electronic Solution, with the Romanian Ministry of Communication and Information Technology as beneficiary.

  7. Evaluating the effects of historical land cover change on summertime weather and climate in New Jersey

    Science.gov (United States)

    Wichansky, Paul Stuart

    The 19th-century agrarian landscape of New Jersey (NJ) and the surrounding region has been extensively transformed to the present-day land cover by urbanization, reforestation, and localized areas of deforestation. This study used a mesoscale atmospheric numerical model to investigate the sensitivity of the warm season climate of NJ to these land cover changes. Reconstructed 1880s-era and present-day land cover datasets were used as surface boundary conditions for a set of simulations performed with the Regional Atmospheric Modeling System (RAMS). Three-member ensembles with historical and present-day land cover were compared to examine the sensitivity of surface air and dewpoint temperatures, rainfall, the individual components of the surface energy budget, horizontal and vertical winds, and the vertical profiles of temperature and humidity to these land cover changes. Mean temperatures for the present-day landscape were 0.3-0.6°C warmer than for the historical landscape over a considerable portion of NJ and the surrounding region, with daily maximum temperatures at least 1.0°C warmer over some of the highly urbanized locations. Reforested regions in the present-day landscape, however, showed a slight cooling. Surface warming was generally associated with repartitioning of net radiation from latent to sensible heat flux, and conversely for cooling. Reduced evapotranspiration from much of the present-day land surface led to dewpoint temperature decreases of 0.3-0.6°C. While urbanization was accompanied by strong surface albedo decreases and increases in net shortwave radiation, reforestation and potential changes in forest composition have generally increased albedos and also enhanced landscape heterogeneity. The increased deciduousness of forests may have further reduced net downward longwave radiation. These land cover changes have modified boundary-layer dynamics by increasing low-level convergence and upper-level divergence in the interior of NJ, especially

  8. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    The purpose of the final cover of a landfill is to contain the waste and to provide for a physical separation between the waste and the environment for protection of public health. Most landfill covers are designed with the primary goal to reduce or prevent infiltration of precipitation...... into the landfill in order to minimize leachate generation. In addition the cover also has to control the release of gases produced in the landfill so the gas can be ventilated, collected and utilized, or oxidized in situ. The landfill cover should also minimize erosion and support vegetation. Finally the cover...... is landscaped in order to fit into the surrounding area/environment or meet specific plans for the final use of the landfill. To fulfill the above listed requirements landfill covers are often multicomponent systems which are placed directly on top of the waste. The top cover may be placed immediately after...

  9. LEGUMINOUS COVER CROPS FOR BANANA PLANTATIONS IN SEMI-ARID REGIONS

    Directory of Open Access Journals (Sweden)

    MATEUS AUGUSTO LIMA QUARESMA

    2017-01-01

    Full Text Available High temperatures and low rainfall characterize the Brazilian semiarid regions. This regional climate demands the adoption of practices that increase the efficiency and sustainability of local farming. This study aimed to assess the ability of two perennial herbaceous leguminous species, calopo and tropical kudzu, to provide permanent soil cover in banana plantations in Jequitinhonha Valley, northeast Minas Gerais state, Brazil. To this end, we evaluated the differences of calopo and tropical kudzu in soil cover capacity and the amount of senescent phytomass deposited on the soil surface, nutrient content in senescent phytomass, as well as their effects on temperature and soil moisture, compared with bare soil in two experimental sites. The results showed that, compared with tropical kudzu, calopo had a higher soil cover capacity and was more effective at increasing organic material and nutrients in the soil owing to the relatively higher amount of senescent phytomass deposited on the soil surface. However, both calopo and tropical kudzu reduced soil temperature and increase soil moisture compared with bare soil. Overall, we concluded that these species can deposit high levels of senescence in the soil, providing several benefits to the cultivation system of banana plants in the semiarid regions.

  10. Cover crops and crop residue management under no-till systems improve soils and environmental quality

    Science.gov (United States)

    Kumar, Sandeep; Wegner, Brianna; Vahyala, Ibrahim; Osborne, Shannon; Schumacher, Thomas; Lehman, Michael

    2015-04-01

    Crop residue harvest is a common practice in the Midwestern USA for the ethanol production. However, excessive removal of crop residues from the soil surface contributes to the degradation of important soil quality indicators such as soil organic carbon (SOC). Addition of a cover crop may help to mitigate these negative effects. The present study was set up to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality indicators and surface greenhouse gas (GHG) fluxes. The study was being conducted on plots located at the North Central Agricultural Research Laboratory (NCARL) in Brookings, South Dakota, USA. Three plots of a corn and soybean (Glycine max (L.) Merr.) rotation under a no-till (NT) system are being monitored for soils and surface gas fluxes. Each plot has three residue removal (high residue removal, HRR; medium residue removal, MRR; and low residue removal, LRR) treatments and two cover crops (cover crops and no cover crops) treatments. Both corn and soybean are represented every year. Gas flux measurements were taken weekly using a closed static chamber method. Data show that residue removal significantly impacted soil quality indicators while more time was needed for an affect from cover crop treatments to be noticed. The LRR treatment resulted in higher SOC concentrations, increased aggregate stability, and increased microbial activity. The LRR treatment also increased soil organic matter (SOM) and particulate organic matter (POM) concentrations. Cover crops used in HRR (high corn residue removal) improved SOC (27 g kg-1) by 6% compared to that without cover crops (25.4 g kg-1). Cover crops significantly impacted POM concentration directly after the residue removal treatments were applied in 2012. CO2 fluxes were observed to increase as temperature increased, while N2O fluxes increased as soil moisture increased. CH4 fluxes were responsive to both increases in temperature and moisture. On average, soils under

  11. Land cover classification of Landsat 8 satellite data based on Fuzzy Logic approach

    Science.gov (United States)

    Taufik, Afirah; Sakinah Syed Ahmad, Sharifah

    2016-06-01

    The aim of this paper is to propose a method to classify the land covers of a satellite image based on fuzzy rule-based system approach. The study uses bands in Landsat 8 and other indices, such as Normalized Difference Water Index (NDWI), Normalized difference built-up index (NDBI) and Normalized Difference Vegetation Index (NDVI) as input for the fuzzy inference system. The selected three indices represent our main three classes called water, built- up land, and vegetation. The combination of the original multispectral bands and selected indices provide more information about the image. The parameter selection of fuzzy membership is performed by using a supervised method known as ANFIS (Adaptive neuro fuzzy inference system) training. The fuzzy system is tested for the classification on the land cover image that covers Klang Valley area. The results showed that the fuzzy system approach is effective and can be explored and implemented for other areas of Landsat data.

  12. Topsoil and fertilizer effects on ground cover growth on calcareous minesoils

    International Nuclear Information System (INIS)

    Kost, D.A.; Vimmerstedt, J.P.

    1997-01-01

    Canopy cover and above ground biomass of herbaceous species was measured in four studies for five years (1989-1993) in southeastern Ohio; on Central Ohio Coal Company's Muskingum Mine, 5 km South of Cumberland. Three studies compared graded cast overburden, standard graded topsoil (30 cm depth), and ripped topsoil. The fourth study lacked the ripped topsoil treatment. In 1987 two studies were seeded with both a standard and a modified mixture of grass and legume species, and two studies used the modified mix only. A nitrogen rate study used 45, 90 or 135 kg/ha of N applied on two occasions, and a phosphorus fertilizer study used rock phosphate amendment at 0, 1120, or 2240 kg/ha and triple superphosphate amendment at 0, 280, or 560 kg/ha. Based on one clipping per year, overall average biomass (Mg/ha dry weight) was slightly greater on standard topsoil (3.34), and ripped topsoil (3.30) than on cast overburden (3.09). Biomass did not differ significantly (p=0.05) on standard topsoil versus cast overburden for 15 of 19 comparisons. Legume biomass (Mg/ha, measured for 3 or 4 years) averaged 0.84 on standard topsoil, 0.75 on ripped topsoil, and 1.16 on cast overburden. In three studies, legume biomass was 50% higher on cast overburden than the topsoils, but differences among the soil surfaces were decreasing by 50% higher on cast overburden than the topsoils, but differences among the soil surfaces were decreasing by 1993. Nitrogen fertilizer increased ground cover only in the year when fertilizer was applied. Phosphorus fertilizer treatments had no significant effects. Ground cover showed no signs of deterioration during the last measurements in 1993. Observations in 1995 indicated dense canopy cover on all soil surfaces with substantial invasion by goldenrods (Solidago spp.) only on topsoils. 16 refs., 4 tabs

  13. Control of water infiltration into near surface LLW disposal units - progress report on field experiments at a Humid Region Site, Beltsville, Maryland

    International Nuclear Information System (INIS)

    O'Donnell, E.; Ridky, R.W.; Schulz, R.K.

    1990-01-01

    Three kinds of waste disposal unit covers or barriers to water infiltration are being investigated. They are: (1) resistive layer barrier, (2) conductive layer barrier, and (3) bioengineering management. The resistive layer barrier consists of compacted earthen material (e.g. clay). The conductive layer barrier consists of a conductive layer in conjunction with a capillary break. As long as unsaturated flow conditions are maintained the conductive layer will wick water around the capillary break. Below grade layered covers such as (1) and (2) will fail if there is appreciable subsidence of the cover. Remedial action for this kind of failure will be difficult. A surface cover, called bioengineering management, is meant to overcome this problem. The bioengineering management surface barrier is easily repairable if damaged by subsidence; therefore, it could be the system of choice under active subsidence conditions. The bioengineering management procedure also has been shown to be effective in dewatering saturated trenches and could be used for remedial action efforts. After cessation of subsidence, that procedure could be replaced by a resistive layer barrier, or perhaps even better, a resistive layer barrier/conductive layer barrier system. This latter system would then give long-term effective protection against water entry to waste and without institutional care. These various concepts are being assessed in six large (70 x 45 x 10 each) lysimeters at Beltsville, Maryland. 6 refs., 21 figs

  14. Using the FORE-SCE model to project land-cover change in the southeastern United States

    Science.gov (United States)

    Sohl, Terry; Sayler, Kristi L.

    2008-01-01

    A wide variety of ecological applications require spatially explicit current and projected land-use and land-cover data. The southeastern United States has experienced massive land-use change since European settlement and continues to experience extremely high rates of forest cutting, significant urban development, and changes in agricultural land use. Forest-cover patterns and structure are projected to change dramatically in the southeastern United States in the next 50 years due to population growth and demand for wood products [Wear, D.N., Greis, J.G. (Eds.), 2002. Southern Forest Resource Assessment. General Technical Report SRS-53. U.S. Department of Agriculture, Forest Service, Southern Research Station, Asheville, NC, 635 pp]. Along with our climate partners, we are examining the potential effects of southeastern U.S. land-cover change on regional climate. The U.S. Geological Survey (USGS) Land Cover Trends project is analyzing contemporary (1973-2000) land-cover change in the conterminous United States, providing ecoregion-by-ecoregion estimates of the rates of change, descriptive transition matrices, and changes in landscape metrics. The FORecasting SCEnarios of future land-cover (FORE-SCE) model used Land Cover Trends data and theoretical, statistical, and deterministic modeling techniques to project future land-cover change through 2050 for the southeastern United States. Prescriptions for future proportions of land cover for this application were provided by ecoregion-based extrapolations of historical change. Logistic regression was used to develop relationships between suspected drivers of land-cover change and land cover, resulting in the development of probability-of-occurrence surfaces for each unique land-cover type. Forest stand age was initially established with Forest Inventory and Analysis (FIA) data and tracked through model iterations. The spatial allocation procedure placed patches of new land cover on the landscape until the scenario

  15. Biomaterials surface science

    CERN Document Server

    Taubert, Andreas; Rodriguez-Cabello, José Carlos

    2013-01-01

    The book provides an overview of the highly interdisciplinary field of surface science in the context of biological and biomedical applications. The covered topics range from micro- and nanostructuring for imparting functionality in a top-down manner to the bottom-up fabrication of gradient surfaces by self-assembly, from interfaces between biomaterials and living matter to smart, stimuli-responsive surfaces, and from cell and surface mechanics to the elucidation of cell-chip interactions in biomedical devices.

  16. Assessing call centers’ success:

    Directory of Open Access Journals (Sweden)

    Hesham A. Baraka

    2013-07-01

    This paper introduces a model to evaluate the performance of call centers based on the Delone and McLean Information Systems success model. A number of indicators are identified to track the call center’s performance. Mapping of the proposed indicators to the six dimensions of the D&M model is presented. A Weighted Call Center Performance Index is proposed to assess the call center performance; the index is used to analyze the effect of the identified indicators. Policy-Weighted approach was used to assume the weights with an analysis of different weights for each dimension. The analysis of the different weights cases gave priority to the User satisfaction and net Benefits dimension as the two outcomes from the system. For the input dimensions, higher priority was given to the system quality and the service quality dimension. Call centers decision makers can use the tool to tune the different weights in order to reach the objectives set by the organization. Multiple linear regression analysis was used in order to provide a linear formula for the User Satisfaction dimension and the Net Benefits dimension in order to be able to forecast the values for these two dimensions as function of the other dimensions

  17. Forest Cover Mapping in Iskandar Malaysia Using Satellite Data

    Science.gov (United States)

    Kanniah, K. D.; Mohd Najib, N. E.; Vu, T. T.

    2016-09-01

    Malaysia is the third largest country in the world that had lost forest cover. Therefore, timely information on forest cover is required to help the government to ensure that the remaining forest resources are managed in a sustainable manner. This study aims to map and detect changes of forest cover (deforestation and disturbance) in Iskandar Malaysia region in the south of Peninsular Malaysia between years 1990 and 2010 using Landsat satellite images. The Carnegie Landsat Analysis System-Lite (CLASlite) programme was used to classify forest cover using Landsat images. This software is able to mask out clouds, cloud shadows, terrain shadows, and water bodies and atmospherically correct the images using 6S radiative transfer model. An Automated Monte Carlo Unmixing technique embedded in CLASlite was used to unmix each Landsat pixel into fractions of photosynthetic vegetation (PV), non photosynthetic vegetation (NPV) and soil surface (S). Forest and non-forest areas were produced from the fractional cover images using appropriate threshold values of PV, NPV and S. CLASlite software was found to be able to classify forest cover in Iskandar Malaysia with only a difference between 14% (1990) and 5% (2010) compared to the forest land use map produced by the Department of Agriculture, Malaysia. Nevertheless, the CLASlite automated software used in this study was found not to exclude other vegetation types especially rubber and oil palm that has similar reflectance to forest. Currently rubber and oil palm were discriminated from forest manually using land use maps. Therefore, CLASlite algorithm needs further adjustment to exclude these vegetation and classify only forest cover.

  18. 78 FR 76218 - Rural Call Completion

    Science.gov (United States)

    2013-12-17

    ... calls to rural areas, and enforce restrictions against blocking, choking, reducing, or restricting calls... to alert the Commission of systemic problems receiving calls from a particular originating long... associated with completing calls to rural areas. These rules will also enhance our ability to enforce...

  19. A computational study on the adsorption configurations and reactions of SiH{sub x}(x = 1-4) on clean and H-covered Si(100) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Le, Thong N-M [Molecular Science and Nano-Materials Laboratory, Institute for Computational Science and Technology, Quang Trung Software Park, Dist. 12, Ho Chi Minh City (Viet Nam); Raghunath, P. [Center for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan (China); Huynh, Lam K., E-mail: lamhuynh.us@gmail.com [Department of Applied Chemistry, School of Biotechnology,International University, VNU-HCMC, Quarter 6, Linh Trung, Thu Duc District, Ho Chi Minh City (Viet Nam); Lin, M.C., E-mail: chemmcl@emory.edu [Center for Interdisciplinary Molecular Science, Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan (China)

    2016-11-30

    Highlights: • Possible adsorption configurations of all adsorbates on Si(100) surface are systematically explored. • The mechanisms leading to the formation of silicon adatoms on the surface are proposed. • The barriers for hydrogen abstractions from the surface are negligible comparing to the barriers for the hydrogen migrations. • The barriers for hydrogen abstractions from the adsorbed speices are negligible comparing to the barriers for the decompositions. - Abstract: Possible adsorption configurations of H and SiH{sub x} (x = 1 − 4) on clean and H-covered Si(100) surfaces are determined by using spin-polarized DFT calculations. The results show that, on the clean surface, the gas-phase hydrogen atom and SiH{sub 3} radicals effectively adsorb on the top sites, while SiH and SiH{sub 2} prefer the bridge sites of the first layer. Another possibility for SiH is to reside on the hollow sites with a triple-bond configuration. For a partially H-coverd Si(100) surface, the mechanism is similar but with higher adsorption energies in most cases. This suggests that the surface species become more stable in the presence of surface hydrogens. The minimum energy paths for the adsorption/migration and reactions of H/SiH{sub x} species on the surfaces are explored using the climbing image-nudged elastic band method. The competitive surface processes for Si thin-film formation from SiH{sub x} precursors are also predicted. The study reveals that the migration of hydrogen adatom is unimportant with respect to leaving open surface sites because of its high barriers (>29.0 kcal/mol). Alternatively, the abstraction of hydrogen adatoms by H/SiH{sub x} radicals is more favorable. Moreover, the removal of hydrogen atoms from adsorbed SiH{sub x}, an essential step for forming Si layers, is dominated by abstraction rather than the decomposition processes.

  20. Long-distance calls in Neotropical primates

    Directory of Open Access Journals (Sweden)

    Oliveira Dilmar A.G.

    2004-01-01

    Full Text Available Long-distance calls are widespread among primates. Several studies concentrate on such calls in just one or in few species, while few studies have treated more general trends within the order. The common features that usually characterize these vocalizations are related to long-distance propagation of sounds. The proposed functions of primate long-distance calls can be divided into extragroup and intragroup ones. Extragroup functions relate to mate defense, mate attraction or resource defense, while intragroup functions involve group coordination or alarm. Among Neotropical primates, several species perform long-distance calls that seem more related to intragroup coordination, markedly in atelines. Callitrichids present long-distance calls that are employed both in intragroup coordination and intergroup contests or spacing. Examples of extragroup directed long-distance calls are the duets of titi monkeys and the roars and barks of howler monkeys. Considerable complexity and gradation exist in the long-distance call repertoires of some Neotropical primates, and female long-distance calls are probably more important in non-duetting species than usually thought. Future research must focus on larger trends in the evolution of primate long-distance calls, including the phylogeny of calling repertoires and the relationships between form and function in these signals.

  1. Mouse-resistant insulated covers keep pipes from freezing

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-01-15

    Fabric wellhead covers and insulated blankets are commonly used at well sites in the Wyoming coalbed methane field to keep surface pipes from freezing. These materials are often chewed up by mice who build nests close to the warm pipes. The mice attract rattlesnakes, a potentially serious problem for the workmen who check the wells daily. Kennon Products of Sheridan, Wyoming solved this problem by making a flexible covering material that has a coating of hardened guard plates that prevents mice from chewing through it. More than a hundred of Kennon's mouse-resistant wellhead covers have been used successfully in the gas fields for over a year. They can be installed in less than 30 minutes and cost only a fraction of what a fiberglass hut costs to purchase and install. Huts are being discouraged for use on federal lands because they alter the nesting patterns of eagles, who perch upon them to hunt rodents. Huts also trap methane gas, which is a potential safety hazard. Kennon's mouse-resistant wellhead covers are lower than the fiberglass huts and blend into the landscape. The company is working on camouflage colours to make wellheads less noticeable. In the future, the company plans to insulate water pipes. 1 fig.

  2. [Culturable psychrotolerant methanotrophic bacteria in landfill cover soil].

    Science.gov (United States)

    Kallistova, A Iu; Montonen, L; Jurgens, G; Munster, U; Kevbrina, M V; Nozhevnikova, A N

    2014-01-01

    Methanotrophs closely related to psychrotolerant members of the genera Methylobacter and Methylocella were identified in cultures enriched at 10@C from landfill cover soil samples collected in the period from April to November. Mesophilic methanotrophs of the genera Methylobacter and Methylosinus were found in cultures enriched at 20 degrees C from the same cover soil samples. A thermotolerant methanotroph related to Methylocaldum gracile was identified in the culture enriched at 40 degrees C from a sample collected in May (the temperature of the cover soil was 11.5-12.5 degrees C). In addition to methanotrophs, methylobacteria of the genera Methylotenera and Methylovorus and members of the genera Verrucomicrobium, Pseudomonas, Pseudoxanthomonas, Dokdonella, Candidatus Protochlamydia, and Thiorhodospira were also identified in the enrichment cultures. A methanotroph closely related to the psychrotolerant species Methylobacter tundripaludum (98% sequence identity of 16S r-RNA genes with the type strain SV96(T)) was isolated in pure culture. The introduction of a mixture of the methanotrophic enrichments, grown at 15 degrees C, into the landfill cover soil resulted in a decrease in methane emission from the landfill surface in autumn (October, November). The inoculum used was demonstrated to contain methanotrophs closely related to Methylobacter tundripaludum SV96.

  3. Minimal families of curves on surfaces

    KAUST Repository

    Lubbes, Niels

    2014-11-01

    A minimal family of curves on an embedded surface is defined as a 1-dimensional family of rational curves of minimal degree, which cover the surface. We classify such minimal families using constructive methods. This allows us to compute the minimal families of a given surface.The classification of minimal families of curves can be reduced to the classification of minimal families which cover weak Del Pezzo surfaces. We classify the minimal families of weak Del Pezzo surfaces and present a table with the number of minimal families of each weak Del Pezzo surface up to Weyl equivalence.As an application of this classification we generalize some results of Schicho. We classify algebraic surfaces that carry a family of conics. We determine the minimal lexicographic degree for the parametrization of a surface that carries at least 2 minimal families. © 2014 Elsevier B.V.

  4. Land Cover

    Data.gov (United States)

    Kansas Data Access and Support Center — The Land Cover database depicts 10 general land cover classes for the State of Kansas. The database was compiled from a digital classification of Landsat Thematic...

  5. Impacts of Land Cover and Land Use Change on the Hydrology of the US-Mexico Border Region, 1992-2011

    Science.gov (United States)

    Bohn, T. J.; Vivoni, E. R.; Mascaro, G.; White, D. D.

    2016-12-01

    The semi-arid US-Mexico border region has been experiencing rapid urbanization and agricultural expansion over the last several decades, due in part to the lifting of trade barriers of the 1994 North American Free Trade Agreement (NAFTA), placing additional pressures on the region's already strained water resources. Here we examine the effects of changes in land cover/use over the period 1992-2011 on the region's hydrology and water resources, using the Variable Infiltration Capacity (VIC) model with an irrigation module to estimate both natural and anthropogenic water fluxes. Land cover has been taken from the National Land Cover Database (NLCD) over the US, and from the Instituto Nacional de Estadística y Geografía (INEGI) database over Mexico, for three snapshots: 1992/3, 2001/2, and 2011. We have performed 3 simulations, one per land cover snapshot, at 6 km resolution, driven by a gridded observed meteorology dataset and a climatology of land surface characteristics derived from remote sensing products. Urban water withdrawal rates were estimated from literature. The primary changes in the region's water budget over the period 1992-2011 consisted of: (1) a shift in agricultural irrigation water withdrawals from the US to Mexico, accompanied by similar shifts in runoff (via agricultural return flow) and evapotranspiration; and (2) a 50% increase in urban water withdrawals, concentrated in the US. Because groundwater supplied most of the additional agricultural withdrawals, and occurred over already over-exploited aquifers, these changes call into question the sustainability of the region's land and water management. By synthesizing the implications of these hydrologic changes, we present a novel view of how NAFTA has altered the US-Mexico border region, possibly in unintended ways.

  6. A grid-based Model for Backwasting at supraglacial Ice Cliffs on a debris-covered Glacier

    Science.gov (United States)

    Buri, P.; Steiner, J. F.; Pellicciotti, F.; Miles, E. S.; Immerzeel, W.

    2014-12-01

    In the Himalaya, debris-covered glaciers cover significant portions of the glacierised area. Their behaviour is not entirely understood, but they seem to experience strong mass losses in direct contradiction with the insulating effect of debris. A characteristic most debris-covered glaciers share is the appearance of cliffs and lakes on their surface. These supraglacial features play a role in surface evolution, dynamics and downwasting of debris-covered glaciers but their actual effects have not been quantified at the glacier scale. Numerous measurements of radiative fluxes at the cliff surface, detailed survey of cliffs geometry and ablation have been conducted on the debris-covered Lirung Glacier, Nepalese Himalayas. We used four 20cm-resolution DEMs obtained from UAV flights to represent the glacier surface to a very detailed degree. As the debris remains stable on slopes up to 30°, ice cliffs show inclinations above this threshold and were clearly represented in the DEMs. Direct measurements and a point-scale cliff-backwasting model have showed that melt patterns over a single cliff are highly variable across and along the ice surface due to non-uniform geometry, varying inclination, aspect and terrain view factors. Variability in observed ablation was large also among cliffs. We therefore developed an energy balance model with a gridded representation of the cliff to understand the melt behaviour at the cliff scale. Previous models assumed the cliff to be a plane with a constant slope and aspect, and extrapolation of melt rates to the glacier scale based on this assumption might be erroneous. Using a grid-based approach allows representation of real inclined areas of the cliff. The detailed surface from the UAV-DEM was taken as initial condition for the model. The model was in close agreement with ablation measurements at numerous stakes located on 3 cliffs. Results show very high variability both along the cliffs' elevation and extension. These cannot be

  7. Pseudospherical surfaces with singularities

    DEFF Research Database (Denmark)

    Brander, David

    2017-01-01

    We study a generalization of constant Gauss curvature −1 surfaces in Euclidean 3-space, based on Lorentzian harmonic maps, that we call pseudospherical frontals. We analyse the singularities of these surfaces, dividing them into those of characteristic and non-characteristic type. We give methods...

  8. The Critical Depth of Freeze-Thaw Soil under Different Types of Snow Cover

    Directory of Open Access Journals (Sweden)

    Qiang Fu

    2017-05-01

    Full Text Available Snow cover is the most common upper boundary condition influencing the soil freeze-thaw process in the black soil farming area of northern China. Snow is a porous dielectric cover, and its unique physical properties affect the soil moisture diffusion, heat conduction, freezing rate and other variables. To understand the spatial distribution of the soil water-heat and the variable characteristics of the critical depth of the soil water and heat, we used field data to analyze the freezing rate of soil and the extent of variation in soil water-heat in a unit soil layer under bare land (BL, natural snow (NS, compacted snow (CS and thick snow (TS treatments. The critical depth of the soil water and heat activity under different snow covers were determined based on the results of the analysis, and the variation fitting curve of the difference sequences on the soil temperature and water content between different soil layers and the surface 5-cm soil layer were used to verify the critical depth. The results were as follows: snow cover slowed the rate of soil freezing, and the soil freezing rate under the NS, CS and TS treatments decreased by 0.099 cm/day, 0.147 cm/day and 0.307 cm/day, respectively, compared with that under BL. In addition, the soil thawing time was delayed, and the effect was more significant with increased snow cover. During freeze-thaw cycles, the extent of variation in the water and heat time series in the shallow soil was relatively large, while there was less variation in the deep layer. There was a critical stratum in the vertical surface during hydrothermal migration, wherein the critical depth of soil water and heat change gradually increased with increasing snow cover. The variance in differences between the surface layer and both the soil water and heat in the different layers exhibited “steady-rising-steady” behavior, and the inflection point of the curve is the critical depth of soil freezing and thawing. This critical

  9. Call 4 Concern: patient and relative activated critical care outreach.

    Science.gov (United States)

    Odell, Mandy; Gerber, Karin; Gager, Melanie

    Patients can experience unexpected deterioration in their physiological condition that can lead to critical illness, cardiac arrest, admission to the intensive care unit and death. While ward staff can identify deterioration through monitoring physiological signs, these signs can be missed, interpreted incorrectly or mismanaged. Rapid response systems using early warning scores can fail if staff do not follow protocols or do not notice or manage deterioration adequately. Nurses often notice deterioration intuitively because of their knowledge of individual patients. Patients and their relatives have the greatest knowledge of patients, and can often pick up subtle signs physiological deterioration before this is identified by staff or monitoring systems. However, this ability has been largely overlooked. Call 4 Concern (C4C) is a scheme where patients and relatives can call critical care teams directly if they are concerned about a patient's condition- it is believed to be the first of its kind in the UK. A C4C feasibility project ran for six months, covering patients being transferred from the intensive care unit to general wards. C4C has the potential to prevent clinical deterioration and is valued by patients and relatives. Concerns of ward staff could be managed through project management. As it is relatively new, this field offers further opportunities for research.

  10. Fuchs-Kliewer phonons of H-covered and clean GaN(1 1 bar 00)

    Science.gov (United States)

    Rink, M.; Himmerlich, M.; Krischok, S.; Kröger, J.

    2018-01-01

    Inelastic electron scattering is used to study surface phonon polaritons on H-covered and clean GaN(1 1 bar 00) surfaces. The Fuchs-Kliewer phonon of GaN(1 1 bar 00) -H gives rise to characteristic signatures of its single and multiple excitation in specular electron energy loss spectra. The loss intensities for multi-phonon scattering processes decrease according to a Poisson distribution. Vibrational spectra of this surface are invariant on the time scale of days reflecting its chemical passivation by the H layer. In contrast, vibrational spectra of pristine GaN(1 1 bar 00) are subject to a pronounced temporal evolution where spectroscopic weight is gradually shifted towards the multiple excitation of the Fuchs-Kliewer phonon. As a consequence, the monotonous decrease of the cross section for multiple quantum excitation as observed for the H-covered surface is not applicable. This remarkable effect is particularly strong in spectra acquired at low primary energies of incident electrons, which hints at processes occurring in the very surface region. Scenarios that may contribute to these observations are discussed.

  11. Detection of land cover changes around Lake Mutirikwi, Zimbabwe ...

    African Journals Online (AJOL)

    Landsat images from 1984, 1995, 2001 and 2011 were used to compute a normalised difference vegetation index (NDVI), which was then used as a proxy for indicating areas infested by surface floating aquatic weeds. Forest and shrubs covered 310.8 km2 in 1984, but had deteriorated by 24.87% to 77.3 km2 in 2011, while ...

  12. Pond dynamics and supraglacial-englacial connectivity on debris-covered Lirung Glacier

    NARCIS (Netherlands)

    Miles, Evan Stewart; Steiner, Jakob|info:eu-repo/dai/nl/119338653; Willis, Ian C.; Buri, Pascal; Immerzeel, Walter Willem|info:eu-repo/dai/nl/290472113; Chesnokova, Anna; Pellicciotti, Francesca

    The hydrological systems of heavily-downwasted debris-covered glaciers differ from clean-ice glaciers due to the hummocky surface and debris mantle of such glaciers, leading to a relatively limited understanding of drainage pathways. Supraglacial ponds represent sinks within the discontinuous

  13. Sleep Quality of Call Handlers Employed in International Call Centers in National Capital Region of Delhi, India.

    Science.gov (United States)

    Raja, J D; Bhasin, S K

    2016-10-01

    Call center sector in India is a relatively new and fast growing industry driving employment and growth in modern India today. Most international call centers in National Capital Region (NCR) of Delhi operate at odd work hours corresponding to a time suitable fortheir international customers. The sleep quality of call handlers employed in these call centers is in jeopardy owing to their altered sleep schedule. To assess the sleep quality and determine its independent predictors among call handlers employed in international call centers in NCR of Delhi. A cross-sectional questionnaire-based study was conducted on 375 call handlers aged 18-39 years employed in international call centers in NCR of Delhi. Sleep quality was assessed using Athens Insomnia scale along with a pre-tested, structured questionnaire. The mean age of respondents was 24.6 (SD 2.4) years. 78% of participants were male. 83.5% of respondents were unmarried. 44.3% of call handlers were cigarette smokers. Physical ailments were reported by 37% call handlers. 77.6% of call handlers had somesuspicion of insomnia or suspected insomnia; the rest had no sleep problem. Smoking, poor social support, heavy workload, lack of relaxation facility at office, and prolonged travel time to office were independent predictors of sleep quality (pSafeguarding their health becomes an occupational health challenge to public health specialists.

  14. Airborne Optical Remote Sensing of Ocean Surface Current Variability

    Science.gov (United States)

    Anderson, S. P.; Zuckerman, S.; Stuart, G.

    2016-02-01

    Accurate and timely knowledge of open ocean surface currents are needed for a variety of engineering and emergency missions, as well as for improving scientific understanding of ocean dynamics. This paper presents surface current observations from a new airborne current measurement capability called the Remote Ocean Current Imaging System (ROCIS). ROCIS exploits space-time processing of airborne ocean wave imagery to produce real-time maps of surface currents every 1 km along the flight track. Post-processing of the data allows for more in depth sensitivity studies than can be undertaken with the real-time measurements alone, providing swaths of current retrievals at higher spatial resolutions. Currents can be calculated on scales down to 100 m, across swaths 3 km wide, along the entire flight path. Here, we report on results for multiple ROCIS data collection flights over the Gulf of Mexico conducted in 2012, 2014 and 2015. We show comparisons to in situ current measurements, explore performance as a function of altitude, dwell, wind speed, and wave height, and discuss sources of error. We present examples of current retrievals revealing mesoscale and submesoscale variability. Lastly, we present horizontal kinetic energy spectra from select flights covering a range of spatial scales from hundreds of meters to hundreds of kilometers.

  15. Changes of coat cover in primitive horses living on a reserve.

    Science.gov (United States)

    Stachurska, A; Robovský, J; Bocian, K; Janczarek, I

    2015-03-01

    Changes in the coat cover are important for mammalian thermoregulation. This is especially true where variable environmental conditions exist throughout the seasons. Coat cover shedding is the replacement of old coat hair with new hair. The process differs in various equids. The aim of the study was to examine the changes in the coat of primitive Polish Konik horses living on a reserve in southeast Poland (50.6319° N). The reserve is located in a temperate climate. The mean temperature is below 0°C in winter (December 8 to March 9) and over 15°C in summer (June 8 to September 8). Five adult mares were included in the study. The study used a specific methodical approach to quantitatively assess coat cover changes. Photos were taken once every 2 wk throughout the whole year to document the state of the mares' coat. MultiScanBase software was used to analyze 260 photos. The percentage of the skin surface covered with short hair in relation to the surface of the body (without the head, neck, and limbs; short hair body [SHB]) was determined. To assess the topography of coat changes, surface parts covered with short hair within 6 regions of the body (shoulder, back, chest, loins, belly, and hindquarters; short hair part [SHP]) were considered separately. The regression coefficient was calculated for the SHB and the air temperature. Correlations in SHP and SHB between the left and right sides of the body were determined. The correlations within the right side of the body concerned particular SHP. As the results show, the coat changes take place at the same time on both sides of the horse's body. In spring, the winter hair is shed, and in the fall, the winter hair grows in longer. High regression (0.901; coat changes. The most important increase of SHB occurs in April and the first half of May, whereas the main decrease of SHB takes place in September. Changes between SHP are highly correlated (0.967-0.994; coat changes demonstrate that the shoulders, back, and loins

  16. Substrate texture affects female cricket walking response to male calling song

    Science.gov (United States)

    Sarmiento-Ponce, E. J.; Sutcliffe, M. P. F.; Hedwig, B.

    2018-03-01

    Field crickets are extensively used as a model organism to study female phonotactic walking behaviour, i.e. their attraction to the male calling song. Laboratory-based phonotaxis experiments generally rely on arena or trackball-based settings; however, no attention has been paid to the effect of substrate texture on the response. Here, we tested phonotaxis in female Gryllus bimaculatus, walking on trackballs machined from methyl-methacrylate foam with different cell sizes. Surface height variations of the trackballs, due to the cellular composition of the material, were measured with profilometry and characterized as smooth, medium or rough, with roughness amplitudes of 7.3, 16 and 180 µm. Female phonotaxis was best on a rough and medium trackball surface, a smooth surface resulted in a significant lower phonotactic response. Claws of the cricket foot were crucial for effective walking. Females insert their claws into the surface pores to allow mechanical interlocking with the substrate texture and a high degree of attachment, which cannot be established on smooth surfaces. These findings provide insight to the biomechanical basis of insect walking and may inform behavioural studies that the surface texture on which walking insects are tested is crucial for the resulting behavioural response.

  17. PRACT (Prototyping Rotation and Association with Cover crop and no Till) - a tool for designing conservation agriculture systems

    NARCIS (Netherlands)

    Naudin, K.; Husson, M.O.; Scopel, E.; Auzoux, S.; Giller, K.E.

    2015-01-01

    Moving to more agroecological cropping systems implies deep changes in the organization of cropping systems. We propose a method for formalizing the process of innovating cropping system prototype design using a tool called PRACT (Prototyping Rotation and Association with Cover crop and no Till)

  18. New course: “Lync – click to call and collaborate with others”

    CERN Multimedia

    2013-01-01

    The presentation will cover the main features of Lync: initiating and receiving phone calls from Lync, chatting (Instant Message), how to stay connected as you were in your office, creating and participating in online meetings, sharing presentations/desktops with other people, using the voice mailbox on Exchange, integration with Outlook, CERN Phone book, phone system etc.   General information about Lync can be found on http://cern.ch/lync, Softphone features of Lync are detailed on http://cern.ch/softphone. Next session: 17 June 2013, from 11 a.m. to 12 a.m. in French. Please register through the Training Catalogue. Lync service and Technical Training

  19. The overall heat transfer of greenhouses covered with PE [polyethylene film] and PVC [polyvinyl chloride film] single layer: The heat insulation efficiency of greenhouses and their covering materials (1)

    International Nuclear Information System (INIS)

    Minagawa, H.; Tachibana, K.

    1982-01-01

    Overall heat transfer of polyethylene film (PE) and polyvinyl chloride film (PVC) were measured in the experimental greenhouses with hot-air heaters on the clear and on the cloudy nights during the period Nov. 1979 to Jan. 1980. Both films are 0.1 mm thick and have different physical properties for long-wave radiation. The heat insulation efficiency of the greenhouses covered with PE and PVC single layer was investigated, and the ratio of floor area to covering area for the experimental greenhouses, which is one of the indices for the heat insulation efficiency of greenhouses, was also taken into consideration. The results are as follows: 1. Using the ratio of the overall heat transfer and the overall heat transfer coefficients for the heat insulation efficiency, the PE-house revealed to be less efficient than the PVC-house. This can be due to PE being more transparent to long-wave radiation than PVC. The advantage in the PVC-house, however, decreased with the increasing of the inside-outside air temperature difference (Figs. 3 and 5). 2. The overall heat transfer coefficients of both greenhouses depended on the inside-outside temperature difference. As the temperature difference increased, the overall heat transfer coefficients decreased (Fig. 5). 3. The overall heat transfer coefficients of both greenhouses were smaller on the cloudy nights than that on the clear nights. When the condensation occurred at the interior film surface, the heat insulation efficiency of both greenhouses was increased, resulting in the decrease of the coefficient. The efficiency of the PE-house was more affected than the PVC-house when the condensation occurred (Figs. 6 and 7). 4. When the inside-outside air temperature difference was small, convective heat transferred from the outside air to the outside cover surface. With an increase in the inside-outside air temperature difference, convective heat flow occurred from the outside cover surface to the outside air. This phenomenon was

  20. Callings and Organizational Behavior

    Science.gov (United States)

    Elangovan, A. R.; Pinder, Craig C.; McLean, Murdith

    2010-01-01

    Current literature on careers, social identity and meaning in work tends to understate the multiplicity, historical significance, and nuances of the concept of calling(s). In this article, we trace the evolution of the concept from its religious roots into secular realms and develop a typology of interpretations using occupation and religious…

  1. Uncertain call likelihood negatively affects sleep and next-day cognitive performance while on-call in a laboratory environment.

    Science.gov (United States)

    Sprajcer, Madeline; Jay, Sarah M; Vincent, Grace E; Vakulin, Andrew; Lack, Leon; Ferguson, Sally A

    2018-05-11

    On-call working arrangements are employed in a number of industries to manage unpredictable events, and often involve tasks that are safety- or time-critical. This study investigated the effects of call likelihood during an overnight on-call shift on self-reported pre-bed anxiety, sleep and next-day cognitive performance. A four-night laboratory-based protocol was employed, with an adaptation, a control and two counterbalanced on-call nights. On one on-call night, participants were instructed that they would definitely be called during the night, while on the other on-call night they were told they may be called. The State-Trait Anxiety Inventory form x-1 was used to investigate pre-bed anxiety, and sleep was assessed using polysomnography and power spectral analysis of the sleep electroencephalographic analysis. Cognitive performance was assessed four times daily using a 10-min psychomotor vigilance task. Participants felt more anxious before bed when they were definitely going to be called, compared with the control and maybe conditions. Conversely, participants experienced significantly less non-rapid eye movement and stage two sleep and poorer cognitive performance when told they may be called. Further, participants had significantly more rapid eye movement sleep in the maybe condition, which may be an adaptive response to the stress associated with this on-call condition. It appears that self-reported anxiety may not be linked with sleep outcomes while on-call. However, this research indicates that it is important to take call likelihood into consideration when constructing rosters and risk-management systems for on-call workers.

  2. Next generation of global land cover characterization, mapping, and monitoring

    Science.gov (United States)

    Giri, Chandra; Pengra, Bruce; Long, J.; Loveland, Thomas R.

    2013-01-01

    Land cover change is increasingly affecting the biophysics, biogeochemistry, and biogeography of the Earth's surface and the atmosphere, with far-reaching consequences to human well-being. However, our scientific understanding of the distribution and dynamics of land cover and land cover change (LCLCC) is limited. Previous global land cover assessments performed using coarse spatial resolution (300 m–1 km) satellite data did not provide enough thematic detail or change information for global change studies and for resource management. High resolution (∼30 m) land cover characterization and monitoring is needed that permits detection of land change at the scale of most human activity and offers the increased flexibility of environmental model parameterization needed for global change studies. However, there are a number of challenges to overcome before producing such data sets including unavailability of consistent global coverage of satellite data, sheer volume of data, unavailability of timely and accurate training and validation data, difficulties in preparing image mosaics, and high performance computing requirements. Integration of remote sensing and information technology is needed for process automation and high-performance computing needs. Recent developments in these areas have created an opportunity for operational high resolution land cover mapping, and monitoring of the world. Here, we report and discuss these advancements and opportunities in producing the next generations of global land cover characterization, mapping, and monitoring at 30-m spatial resolution primarily in the context of United States, Group on Earth Observations Global 30 m land cover initiative (UGLC).

  3. Scattering of hyperthermal argon atoms from clean and D-covered Ru surfaces

    NARCIS (Netherlands)

    Ueta, H.; Gleeson, M.A.; Kleyn, A.W.

    2011-01-01

    Hyperthermal Ar atoms were scattered from a Ru(0001) surface held at temperatures of 180, 400 and 600 K, and from a Ru(0001)-(1×1)D surface held at 114 and 180 K. The resultant angular intensity and energy distributions are complex. The in-plane angular distributions have narrow (FWHM ≤ 10°)

  4. Interrelationships between soil cover and plant cover depending on land use

    Directory of Open Access Journals (Sweden)

    Tiina Köster

    2013-05-01

    Full Text Available Interrelationships between soil cover and plant cover of normally developed (or postlithogenic mineral soils are analysed on the basis of four sampling soil groups. The four-link pedo-ecological sequence of analysed soils, rendzinas → brown soils → pseudopodzolic soils → gley-podzols, forms a representative cross section in relation to the normal mineral soils of Estonia. All groups differ substantially from each other in terms of soil properties (calcareousness, acidity, nutrition conditions, profile fabric and humus cover. The primary tasks of the research were (1 to elucidate the main pedo-ecological characteristics of the four soil groups and their suitability for plant cover, (2 to evaluate comparatively soils in terms of productivity, sustainability, biodiversity and environmental protection ability and (3 to analyse possibilities for ecologically sound matching of soil cover with suitable plant cover. On the basis of the same material, the influence of land-use change on humus cover (epipedon fabric, properties of the entire soil cover and soil–plant interrelationship were also analysed. An ecosystem approach enables us to observe particularities caused by specific properties of a soil type (species, variety in biological turnover and in the formation of biodiversity.

  5. Electrochemical modification of chromium surfaces using 4-nitro- and4-fluorobenzenediazonium salts

    DEFF Research Database (Denmark)

    Hinge, Mogens; Cecatto, Marcel; Kingshott, Peter

    2009-01-01

    Chromium surfaces can be electrografted with organic surface films using 4-nitro- or 4-fluorobenzenediazonium salts, despite the fact that the surfaces are covered with a protective chromium oxide layer......Chromium surfaces can be electrografted with organic surface films using 4-nitro- or 4-fluorobenzenediazonium salts, despite the fact that the surfaces are covered with a protective chromium oxide layer...

  6. Egypt satellite images for land surface characterization

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay

    images used for mapping the vegetation cover types and other land cover types in Egypt. The mapping ranges from 1 km resolution to 30 m resolution. The aim is to provide satellite image mapping with land surface characteristics relevant for roughness mapping.......Satellite images provide information on the land surface properties. From optical remote sensing images in the blue, green, red and near-infrared part of the electromagnetic spectrum it is possible to identify a large number of surface features. The report briefly describes different satellite...

  7. Impacts of Land Cover and Seasonal Variation on Maximum Air Temperature Estimation Using MODIS Imagery

    Directory of Open Access Journals (Sweden)

    Yulin Cai

    2017-03-01

    Full Text Available Daily maximum surface air temperature (Tamax is a crucial factor for understanding complex land surface processes under rapid climate change. Remote detection of Tamax has widely relied on the empirical relationship between air temperature and land surface temperature (LST, a product derived from remote sensing. However, little is known about how such a relationship is affected by the high heterogeneity in landscapes and dynamics in seasonality. This study aims to advance our understanding of the roles of land cover and seasonal variation in the estimation of Tamax using the MODIS (Moderate Resolution Imaging Spectroradiometer LST product. We developed statistical models to link Tamax and LST in the middle and lower reaches of the Yangtze River in China for five major land-cover types (i.e., forest, shrub, water, impervious surface, cropland, and grassland and two seasons (i.e., growing season and non-growing season. Results show that the performance of modeling the Tamax-LST relationship was highly dependent on land cover and seasonal variation. Estimating Tamax over grasslands and water bodies achieved superior performance; while uncertainties were high over forested lands that contained extensive heterogeneity in species types, plant structure, and topography. We further found that all the land-cover specific models developed for the plant non-growing season outperformed the corresponding models developed for the growing season. Discrepancies in model performance mainly occurred in the vegetated areas (forest, cropland, and shrub, suggesting an important role of plant phenology in defining the statistical relationship between Tamax and LST. For impervious surfaces, the challenge of capturing the high spatial heterogeneity in urban settings using the low-resolution MODIS data made Tamax estimation a difficult task, which was especially true in the growing season.

  8. Theorizing Land Cover and Land Use Changes: The Case of Tropical Deforestation

    Science.gov (United States)

    Walker, Robert

    2004-01-01

    This article addresses land-cover and land-use dynamics from the perspective of regional science and economic geography. It first provides an account of the so-called spatially explicit model, which has emerged in recent years as a key empirical approach to the issue. The article uses this discussion as a springboard to evaluate the potential utility of von Thuenen to the discourse on land-cover and land-use change. After identifying shortcomings of current theoretical approaches to land use in mainly urban models, the article filters a discussion of deforestation through the lens of bid-rent and assesses its effectiveness in helping us comprehend the destruction of tropical forest in the Amazon basin. The article considers the adjustments that would have to be made to existing theory to make it more useful to the empirical issues.

  9. Field performance of alternative landfill covers vegetated with cottonwood and eucalyptus trees.

    Science.gov (United States)

    Abichou, Tarek; Musagasa, Jubily; Yuan, Lei; Chanton, Jeff; Tawfiq, Kamal; Rockwood, Donald; Licht, Louis

    2012-01-01

    A field study was conducted to assess the ability of landfill covers to control percolation into the waste. Performance of one conventional cover was compared to that of two evapotranspiration (ET) tree covers, using large (7 x 14 m) lined lysimeters at the Leon County Solid Waste management facility in Tallahassee, Florida. Additional unlined test sections were also constructed and monitored in order to compare soil water storage, soil temperature, and tree growth inside lysimeters and in unlined test sections. The unlined test sections were in direct contact with landfill gas. Surface runoff on the ET covers was a small proportion of the water balance (1% of precipitation) as compared to 13% in the conventional cover. Percolation in the ET covers averaged 17% and 24% of precipitation as compared to 33% in the conventional cover. On average, soil water storage was higher in the lined lysimeters (429 mm) compared to unlined test sections (408 mm). The average soil temperature in the lysimeters was lower than in the unlined test sections. The average tree height inside the lysimeters was not significantly lower (8.04 mfor eucalyptus and 7.11 mfor cottonwood) than outside (8.82 m for eucalyptus and 8.01 m for cottonwood). ET tree covers vegetated with cottonwood or eucalyptus are feasible for North Florida climate as an alternative to GCL covers.

  10. Fine Resolution Probabilistic Land Cover Classification of Landscapes in the Southeastern United States

    Directory of Open Access Journals (Sweden)

    Joseph St. Peter

    2018-03-01

    Full Text Available Land cover classification provides valuable information for prioritizing management and conservation operations across large landscapes. Current regional scale land cover geospatial products within the United States have a spatial resolution that is too coarse to provide the necessary information for operations at the local and project scales. This paper describes a methodology that uses recent advances in spatial analysis software to create a land cover classification over a large region in the southeastern United States at a fine (1 m spatial resolution. This methodology used image texture metrics and principle components derived from National Agriculture Imagery Program (NAIP aerial photographic imagery, visually classified locations, and a softmax neural network model. The model efficiently produced classification surfaces at 1 m resolution across roughly 11.6 million hectares (28.8 million acres with less than 10% average error in modeled probability. The classification surfaces consist of probability estimates of 13 visually distinct classes for each 1 m cell across the study area. This methodology and the tools used in this study constitute a highly flexible fine resolution land cover classification that can be applied across large extents using standard computer hardware, common and open source software and publicly available imagery.

  11. Care and calls

    DEFF Research Database (Denmark)

    Paasch, Bettina Sletten

    -centred care through the use of tactile resources and embodied orientations while they attend to the phone call. Experienced nurses Thus perform multiactivity by distributing attention towards both the patient and the phone, and the analysis shows that their concrete ways of doing so depend on the complex...... they are telephoned during interactions with patients are not universal. Indeed different strategies have evolved in other hospital departments. Not only does this thesis contribute insights into the way nurses manage phone calls during interactions with patients, but by subscribing to a growing body of embodied...... of human interaction....

  12. Biofilm Surface Density Determines Biocide Effectiveness

    Directory of Open Access Journals (Sweden)

    Sara Bas

    2017-12-01

    Full Text Available High resistance of biofilms for chemical challenges is a serious industrial and medical problem. In this work a gradient of surface covered with biofilm has been produced and correlated to the effectiveness of different commercially available oxidative biocides. The results for thin Escherichia coli biofilms grown in rich media supplemented with glucose or lactose on glass or poly methyl methacrylate surfaces indicate that the effectiveness of hydrogen peroxide or chlorine dioxide and quaternary ammonium compounds is inversely proportional to the fraction of the surface covered with the biofilm. In areas where biofilm covered more than 90% of the available surface the biocide treatment was inefficient after 60 min of incubation. The combined effect of oxidant and surfactant increased the effectiveness of the biocide. On the other hand, the increased biofilm viscoelasticity reduced biocide effectiveness. The results emphasize differential biocide effectiveness depending on the fraction of the attached bacterial cells. The results suggest that biofilm biocide resistance is an acquired property that increases with biofilm maturation. The more dense sessile structures present lower log reductions compared to less dense ones.

  13. Silicone covered vs. Non- covered endotracheal self expandable metallic stent: An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Do, Young Soo; Lee, Byung Hee; Kim, Soo Ah; Kim, Kie Hwan; Chin, Soo Yil; Cho, Kyung Ja; Cho, Dae Soon [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1994-10-15

    To evaluate pathologic changes of the trachea and the lung after insertion of silicone covered and non covered Gianturco stent in the trachea of dog. Silicone covered(covered) and non covered(bare) Gianturco stent, six in each, were inserted into the tracheal lumen of six consecutive dogs. After 1-10 weeks observation, the dogs were sacrificed and their tracheas and lungs were examined grossly and histopathologically. Serial chest radiographs were performed to evaluate pneumonia and stent migration every 3-5 days. Pneumonia was observed in one of bare stent group and five of covered stent group. Stent migration was noted in three of covered stent group. In bare stent group, the epithelium of the trachea was markedly thickened by hyperplasia and stent was covered by granulation tissue from 6 weeks after stent insertion. Inflammation was focal at contact site between the stent and the trachea. In covered stent group, the epithelium was denuded at multiple areas and there were multifocal squamous metaplasia of the mucosa. Inflammatory reaction of the trachea was diffuse. Inflammatory reaction was more severe and stent migration was more frequent in covered stent group. The use of covered stent in the trachea should be studied further.

  14. 488-D Ash Basin Vegetative Cover Treatibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Christopher; Marx, Don; Blake, John; Adriano, Domy; Koo, Bon-Jun; Czapka, Stephen

    2003-01-01

    The 488-D Ash Basin is an unlined containment basin that received ash and coal reject material from the operation of a powerhouse at the USDOE's Savannah River Site, SC. They pyretic nature of the coal rejects has resulted in the formation of acidic drainage (AD), which has contributed to groundwater deterioration and threatens biota in down gradient wetlands. Establishment of a vegetative cover was examined as a remedial alternative for reducing AD generation within this system by enhanced utilization of rainwater and subsequent non-point source water pollution control. The low nutrient content, high acidity, and high salinity of the basin material, however, was deleterious to plant survivability. As such, studies to identify suitable plant species and potential adaptations, and pretreatment techniques in the form of amendments, tilling, and/or chemical stabilization were needed. A randomized block design consisting of three subsurface treatments (blocks) and five duplicated surface amendments (treatments) was developed. One hundred inoculated pine trees were planted on each plot. Herbaceous species were also planted on half of the plots in duplicated 1-m2 beds. After two growing seasons, deep ripping, subsurface amendments and surface covers were shown to be essential for the successful establishment of vegetation on the basin. This is the final report of the study.

  15. Global warming: Sea ice and snow cover

    International Nuclear Information System (INIS)

    Walsh, J.E.

    1993-01-01

    In spite of differences among global climate simulations under scenarios where atmospheric CO 2 is doubled, all models indicate at least some amplification of greenouse warming at the polar regions. Several decades of recent data on air temperature, sea ice, and snow cover of the high latitudes of the Northern Hemisphere are summarized to illustrate the general compatibility of recent variations in those parameters. Despite a data void over the Arctic Ocean, some noteworthy patterns emerge. Warming dominates in winter and spring, as projected by global climate models, with the warming strongest over subpolar land areas of Alaska, northwestern Canada, and northern Eurasia. A time-longitude summary of Arctic sea ice variations indicates that timescales of most anomalies range from several months to several years. Wintertime maxima of total sea ice extent contain no apparent secular trends. The statistical significance of trends in recent sea ice variations was evaluated by a Monte Carlo procedure, showing a statistically significant negative trend in the summer. Snow cover data over the 20-y period of record show a noticeable decrease of Arctic snow cover in the late 1980s. This is of potential climatic significance since the accompanying decrease of surface albedo leads to a rapid increase of solar heating. 21 refs., 3 figs., 1 tab

  16. Control of water infiltration into near surface LLW disposal units-progress report on field experiments at a humid region site, Beltsville, Maryland

    International Nuclear Information System (INIS)

    O'Donnell, E.; Ridky, R.W.; Schulz, R.K.

    1994-01-01

    The study's objective is to assess means for controlling water infiltration through waste disposal unit covers in humid regions. Experimental work is being performed in large-scale lysimeters (75'x45'x10') at Beltsville, MD, and results of the assessment are applicable to disposal of low-level radioactive waste (LLW), uranium mill tailings, hazardous waste, and sanitary landfills. Three kinds of waste disposal unit covers or barriers to water infiltration are being investigated. They are: (1) resistive layer barrier, (2) conductive layer barrier, and (3) bioengineering management. The conductive layer barrier consists of a conductive layer in conjunction with a capillary break. As long as unsaturated flow conditions are maintained, the conductive layer will wick water around the capillary break. Below-grade layered covers such as (1) and (2) will fail if there is appreciable subsidence of the cover. Remedial action for this kind of failure will be difficult. A surface cover, called bioengineering management, is meant to overcome this problem. The bioengineering management surface barrier is easily repairable if damaged by subsidence; therefore, it could be the system of choice under active subsidence conditions. The bioengineering management procedure also has been shown to be effective in dewatering saturated trenches and could be used for remedial action efforts. After cessation of subsidence, that procedure could be replaced by a resistive layer barrier, or perhaps even better, a resistive layer barrier/conductive layer barrier system. This latter system would then give long-term effective protection against water entry into waste and without institutional care

  17. Ion-beam crystallography of clean and adsorbate covered metal surfaces

    International Nuclear Information System (INIS)

    Veen, J.F. van der.

    1978-01-01

    This thesis deals with the precise determination of atomic positions in the very first layer of a single-crystal surface. The technique of medium energy ion scattering in conjunction with channeling and blocking is used. The principle of this method is based on simple shadowing and blocking effects and relies on geometrical considerations only. (Auth.)

  18. Short-Range Acoustic Propagation Using Mobile Transmitters Under Arctic Ice Cover

    Science.gov (United States)

    2017-09-01

    Canadian Basin, the surface layer is called the Polar Surface Water , extends down to around 200 meters , and is made up of the Polar Mixed Layer (PML...mixing and turbulence (Nelson 2016). Below the PSW is the PWW, down to a depth of approximately 200 meters . Below the PWW is the Atlantic Water (AW...which again has a temperature maximum, and extends to a depth of around 1000 meters . Below the AW is the deep water , from 1000 meters to the bottom

  19. Self-cleaning skin-like prosthetic polymer surfaces

    Science.gov (United States)

    Simpson, John T [Clinton, TN; Ivanov, Ilia N [Knoxville, TN; Shibata, Jason [Manhattan Beach, CA

    2012-03-27

    An external covering and method of making an external covering for hiding the internal endoskeleton of a mechanical (e.g., prosthetic) device that exhibits skin-like qualities is provided. The external covering generally comprises an internal bulk layer in contact with the endoskeleton of the prosthetic device and an external skin layer disposed about the internal bulk layer. The external skin layer is comprised of a polymer composite with carbon nanotubes embedded therein. The outer surface of the skin layer has multiple cone-shaped projections that provide the external skin layer with superhydrophobicity. The carbon nanotubes are preferably vertically aligned between the inner surface and outer surface of the external skin layer in order to provide the skin layer with the ability to transmit heat. Superhydrophobic powders may optionally be used as part of the polymer composite or applied as a coating to the surface of the skin layer to enhance superhydrophobicity.

  20. MODELLING THE RELATIONSHIP BETWEEN LAND SURFACE TEMPERATURE AND LANDSCAPE PATTERNS OF LAND USE LAND COVER CLASSIFICATION USING MULTI LINEAR REGRESSION MODELS

    Directory of Open Access Journals (Sweden)

    A. M. Bernales

    2016-06-01

    Full Text Available The threat of the ailments related to urbanization like heat stress is very prevalent. There are a lot of things that can be done to lessen the effect of urbanization to the surface temperature of the area like using green roofs or planting trees in the area. So land use really matters in both increasing and decreasing surface temperature. It is known that there is a relationship between land use land cover (LULC and land surface temperature (LST. Quantifying this relationship in terms of a mathematical model is very important so as to provide a way to predict LST based on the LULC alone. This study aims to examine the relationship between LST and LULC as well as to create a model that can predict LST using class-level spatial metrics from LULC. LST was derived from a Landsat 8 image and LULC classification was derived from LiDAR and Orthophoto datasets. Class-level spatial metrics were created in FRAGSTATS with the LULC and LST as inputs and these metrics were analysed using a statistical framework. Multi linear regression was done to create models that would predict LST for each class and it was found that the spatial metric “Effective mesh size” was a top predictor for LST in 6 out of 7 classes. The model created can still be refined by adding a temporal aspect by analysing the LST of another farming period (for rural areas and looking for common predictors between LSTs of these two different farming periods.

  1. Surface Characterization for Land-Atmosphere Studies of CLASIC

    Science.gov (United States)

    Jackson, T. J.; Kustas, W.; Torn, M. S.; Meyers, T.; Prueger, J.; Fischer, M. L.; Avissar, R.; Yueh, S.; Anderson, M.; Miller, M.

    2006-12-01

    The Cloud and Land Surface Interaction Campaign will focus on interactions between the land surface, convective boundary layer, and cumulus clouds. It will take place in the Southern Great Plains (SGP) area of the U.S, specifically within the US DOE ARM Climate Research Facility. The intensive observing period will be June of 2007, which typically covers the winter wheat harvest in the region. This region has been the focus of several related experiments that include SGP97, SGP99, and SMEX03. For the land surface, some of the specific science questions include 1) how do spatial variations in land cover along this trajectory modulate the cloud structure and the low-level water vapor budget, 2) what are the relationships between land surface characteristics (i.e., soil texture, vegetation type and fractional cover) and states (particularly soil moisture and surface temperature) and the resulting impact of the surface energy balance on boundary layer and cloud structure and dynamics and aerosol loading; and 3) what is the interplay between cumulus cloud development and surface energy balance partitioning between latent and sensible heat, and implications for the carbon flux? Most of these objectives will require flux and state measurements throughout the dominant land covers and distributed over the geographic domain. These observations would allow determining the level of up- scaling/aggregation required in order to understand the impact of landscape changes affecting energy balance/flux partitioning and impact on cloud/atmospheric dynamics. Specific contributions that are planned to be added to CLASIC include continuous tower-based monitoring of surface fluxes for key land cover types prior to, during, and post-IOP, replicate towers to quantify flux variance within each land cover, boundary layer properties and fluxes from a helicopter-based system, airplane- and satellite-based flux products throughout the region, aircraft- and tower-based concentration data for

  2. Optimal land use/cover classification using remote sensing imagery for hydrological modelling in a Himalayan watershed

    NARCIS (Netherlands)

    Sameer Saran,; Sterk, G.; Kumar, S.

    2007-01-01

    Land use/cover is an important watershed surface characteristic that affects surface runoff and erosion. Many of the available hydrological models divide the watershed into Hydrological Response Units (HRU), which are spatial units with expected similar hydrological behaviours. The division into

  3. Correlated declines in Pacific arctic snow and sea ice cover

    Science.gov (United States)

    Stone, Robert P.; Douglas, David C.; Belchansky, Gennady I.; Drobot, Sheldon

    2005-01-01

    Simulations of future climate suggest that global warming will reduce Arctic snow and ice cover, resulting in decreased surface albedo (reflectivity). Lowering of the surface albedo leads to further warming by increasing solar absorption at the surface. This phenomenon is referred to as “temperature–albedo feedback.” Anticipation of such a feedback is one reason why scientists look to the Arctic for early indications of global warming. Much of the Arctic has warmed significantly. Northern Hemisphere snow cover has decreased, and sea ice has diminished in area and thickness. As reported in the Arctic Climate Impact Assessment in 2004, the trends are considered to be outside the range of natural variability, implicating global warming as an underlying cause. Changing climatic conditions in the high northern latitudes have influenced biogeochemical cycles on a broad scale. Warming has already affected the sea ice, the tundra, the plants, the animals, and the indigenous populations that depend on them. Changing annual cycles of snow and sea ice also affect sources and sinks of important greenhouse gases (such as carbon dioxide and methane), further complicating feedbacks involving the global budgets of these important constituents. For instance, thawing permafrost increases the extent of tundra wetlands and lakes, releasing greater amounts of methane into the atmosphere. Variable sea ice cover may affect the hemispheric carbon budget by altering the ocean–atmosphere exchange of carbon dioxide. There is growing concern that amplification of global warming in the Arctic will have far-reaching effects on lower latitude climate through these feedback mechanisms. Despite the diverse and convincing observational evidence that the Arctic environment is changing, it remains unclear whether these changes are anthropogenically forced or result from natural variations of the climate system. A better understanding of what controls the seasonal distributions of snow and ice

  4. How to call the Fire Brigade

    CERN Multimedia

    2003-01-01

    The telephone numbers for the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from "wired" telephones, however, from mobile phones it leads to non-CERN emergency services.

  5. Understanding snow-transport processes shaping the mountain snow-cover

    Directory of Open Access Journals (Sweden)

    R. Mott

    2010-12-01

    Full Text Available Mountain snow-cover is normally heterogeneously distributed due to wind and precipitation interacting with the snow cover on various scales. The aim of this study was to investigate snow deposition and wind-induced snow-transport processes on different scales and to analyze some major drift events caused by north-west storms during two consecutive accumulation periods. In particular, we distinguish between the individual processes that cause specific drifts using a physically based model approach. Very high resolution wind fields (5 m were computed with the atmospheric model Advanced Regional Prediction System (ARPS and used as input for a model of snow-surface processes (Alpine3D to calculate saltation, suspension and preferential deposition of precipitation. Several flow features during north-west storms were identified with input from a high-density network of permanent and mobile weather stations and indirect estimations of wind directions from snow-surface structures, such as snow dunes and sastrugis. We also used Terrestrial and Airborne Laser Scanning measurements to investigate snow-deposition patterns and to validate the model. The model results suggest that the in-slope deposition patterns, particularly two huge cross-slope cornice-like drifts, developed only when the prevailing wind direction was northwesterly and were formed mainly due to snow redistribution processes (saltation-driven. In contrast, more homogeneous deposition patterns on a ridge scale were formed during the same periods mainly due to preferential deposition of precipitation. The numerical analysis showed that snow-transport processes were sensitive to the changing topography due to the smoothing effect of the snow cover.

  6. Advanced surface technology a holistic view on the extensive and intertwined world of applied surface engineering

    CERN Document Server

    Moller, Per

    2013-01-01

    These two volumes serve as an inclusive and practical reference in manufacturing as well as a comprehensive text for university-level course work. Before delving into the variety of conventional and emerging surface finishing processes available to the 21st century practitioner, the authors cover the principles behind the processes, including wear and other mechanical properties, corrosion and electrochemistry. Throughout, the material also covers testing, property measurement and a generic introduction to basically all surface relevant characterization techniques, keyed to the specific process and application under discussion.

  7. Make your Boy surface

    OpenAIRE

    Ogasa, Eiji

    2013-01-01

    This is an introductory article on the Boy surface. Boy found that RP2 can be immersed into R3 and published it 1901. (The image of) the immersion is called the Boy surface after Boy's discovery. We have created a way to construct the Boy surface by using a pair of scissors, a piece of paper, and a strip of scotch tape. In this article we introduce the way.

  8. Canopy cover negatively affects arboreal ant species richness in a tropical open habitat

    Directory of Open Access Journals (Sweden)

    A. C. M. Queiroz

    Full Text Available Abstract We tested the hypothesis of a negative relationship between vegetation characteristics and ant species richness in a Brazilian open vegetation habitat, called candeial. We set up arboreal pitfalls to sample arboreal ants and measured the following environmental variables, which were used as surrogate of environmental heterogeneity: tree richness, tree density, tree height, circumference at the base of the plants, and canopy cover. Only canopy cover had a negative effect on the arboreal ant species richness. Vegetation characteristics and plant species composition are probably homogeneous in candeial, which explains the lack of relationship between other environmental variables and ant richness. Open vegetation habitats harbor a large number of opportunistic and generalist species, besides specialist ants from habitats with high temperatures. An increase in canopy cover decreases sunlight incidence and may cause local microclimatic differences, which negatively affect the species richness of specialist ants from open areas. Canopy cover regulates the richness of arboreal ants in open areas, since only few ant species are able to colonize sites with dense vegetation; most species are present in sites with high temperature and luminosity. Within open vegetation habitats the relationship between vegetation characteristics and species richness seems to be the opposite from closed vegetation areas, like forests.

  9. Utilization of satellite remote sensing data on land surface characteristics in water and heat balance component modeling for vegetation covered territories

    Science.gov (United States)

    Muzylev, Eugene; Uspensky, Alexander; Startseva, Zoya; Volkova, Elena; Kukharsky, Alexander; Uspensky, Sergey

    2010-05-01

    The model of vertical water and heat transfer in the "soil-vegetation-atmosphere" system (SVAT) for vegetation covered territory has been developed, allowing assimilating satellite remote sensing data on land surface condition as well as accounting for heterogeneities of vegetation and meteorological characteristics. The model provides the calculation of water and heat balance components (such as evapotranspiration Ev, soil water content W, sensible and latent heat fluxes and others ) as well as vertical soil moisture and temperature distributions, temperatures of soil surface and foliage, land surface brightness temperature for any time interval within vegetation season. To describe the landscape diversity soil constants and leaf area index LAI, vegetation cover fraction B, and other vegetation characteristics are used. All these values are considered to be the model parameters. Territory of Kursk region with square about 15 thousands km2 situated in the Black Earth zone of Central Russia was chosen for investigation. Satellite-derived estimates of land surface characteristics have been constructed under cloud-free condition basing AVHRR/NOAA, MODIS/EOS Terra and EOS Aqua, SEVIRI/Meteosat-8, -9 data. The developed technologies of AVHRR data thematic processing have been refined providing the retrieval of surface skin brightness temperature Tsg, air foliage temperature Ta, efficient surface temperature Ts.eff and emissivity E, as well as derivation of vegetation index NDVI, B, and LAI. The linear regression estimators for Tsg, Ta and LAI have been built using representative training samples for 2003-2009 vegetation seasons. The updated software package has been applied for AVHRR data thematic processing to generate named remote sensing products for various dates of the above vegetation seasons. The error statistics of Ta, Ts.eff and Тsg derivation has been investigated for various samples using comparison with in-situ measurements that has given RMS errors in the

  10. Mekong Land Cover Dasboard: Regional Land Cover Mointoring Systems

    Science.gov (United States)

    Saah, D. S.; Towashiraporn, P.; Aekakkararungroj, A.; Phongsapan, K.; Triepke, J.; Maus, P.; Tenneson, K.; Cutter, P. G.; Ganz, D.; Anderson, E.

    2016-12-01

    SERVIR-Mekong, a USAID-NASA partnership, helps decision makers in the Lower Mekong Region utilize GIS and Remote Sensing information to inform climate related activities. In 2015, SERVIR-Mekong conducted a geospatial needs assessment for the Lower Mekong countries which included individual country consultations. The team found that many countries were dependent on land cover and land use maps for land resource planning, quantifying ecosystem services, including resilience to climate change, biodiversity conservation, and other critical social issues. Many of the Lower Mekong countries have developed national scale land cover maps derived in part from remote sensing products and geospatial technologies. However, updates are infrequent and classification systems do not always meet the needs of key user groups. In addition, data products stop at political boundaries and are often not accessible making the data unusable across country boundaries and with resource management partners. Many of these countries rely on global land cover products to fill the gaps of their national efforts, compromising consistency between data and policies. These gaps in national efforts can be filled by a flexible regional land cover monitoring system that is co-developed by regional partners with the specific intention of meeting national transboundary needs, for example including consistent forest definitions in transboundary watersheds. Based on these facts, key regional stakeholders identified a need for a land cover monitoring system that will produce frequent, high quality land cover maps using a consistent regional classification scheme that is compatible with national country needs. SERVIR-Mekong is currently developing a solution that leverages recent developments in remote sensing science and technology, such as Google Earth Engine (GEE), and working together with production partners to develop a system that will use a common set of input data sources to generate high

  11. Escoamento superficial e desagregação do solo em entressulcos em solo franco-argilo-arenoso com resíduos vegetais Interrill surface runoff and soil detachment on a sandy clay loam soil with residue cover

    Directory of Open Access Journals (Sweden)

    Elemar Antonino Cassol

    2004-07-01

    Full Text Available A presença de resíduos vegetais sobre a superfície do solo altera as características do escoamento superficial gerado pela chuva e a desagregação e transporte de sedimento resultantes do processo erosivo. O objetivo deste trabalho foi avaliar as condições hidráulicas e as relações de desagregação do solo e de resistência ao escoamento com a presença de resíduos vegetais na erosão em entressulcos. O experimento foi realizado no laboratório, com um Argissolo Vermelho distrófico típico, em parcelas com 0,10 m m-1 de declive sob chuva simulada. O solo foi coberto por resíduos vegetais de palha de soja, nas doses de 0, 0,05, 0,1, 0,2, 0,4 e 0,8 kg m-2. O aumento na cobertura do solo (CS com resíduos vegetais elevou a altura da lâmina de escoamento e a rugosidade hidráulica e reduziu a velocidade média do escoamento, provocada pelo aumento das forças viscosas promovida pela interposição física dos resíduos ao escoamento. O resultado é a redução na taxa de desagregação do solo (Di. A Di foi de 5,35x10-4 kg m-2 s-1 para solo descoberto e 1,50x10-5 kg m-2 s-1 em solo com 100% de cobertura na maior dose de palha. Os modelos de Laflen e potencial foram adequados para estimar o coeficiente de cobertura para resíduo em contato direto com a superfície do solo em função da cobertura do solo.Soil surface cover with crop residue modifies surface flow characteristics, generated by excess rainfall, and soil detachment and sediment transport resulting from the erosion process. The objective of this study was to evaluate the hydraulic conditions, detachment and flow resistance on interrill erosion on soil covered with residue. The experiment was conducted in the laboratory, on a Hapludult soil at a slope of 0.10 m m-1, under simulated rainfall and soil surface covered with soybean residue at the rates of 0, 0.05, 0.1, 0.2, 0.4, and 0.8 kg m-2. The increase in soil surface cover (SC with residue, caused an increase in water flow

  12. Hydrogenation of Phenylacetylene to Styrene on Pre-C_xH_y- and C-Covered Cu(111) Single Crystal Catalysts

    International Nuclear Information System (INIS)

    Sohn, Young Ku; Wei, Wei; White, John M.

    2011-01-01

    Thermal hydrogenation of phenylacetylene (PA, C_8H_6) to styrene (C_8H_8) on pre-C_xH_y- and C-covered Cu(111) single crystal substrates has been studied using temperature-programmed desorption (TPD) mass spectrometry. Chemisorbed PA with an acetylene group has been proved to be associated with hydrogen of pre-adsorbed C_xH_y to form styrene (104 amu) on Cu surface. For the parent (PA) mass (102 amu) TPD profile, the TPD peaks at 360 K and 410 K are assigned to chemisorbed vertically aligned PA and flat-lying cross-bridged PA, respectively (J. Phys. Chem. C 2007, 111, 5101). The relative I_3_6_0_K/I_4_1_0_K TPD ratio dramatically increases with increasing pre-adsorbed C_xH_y before dosing PA, while the ratio does not increase for pre-C-covered surface. For PA on pre-C_xH_y-covered Cu(111) surface, styrene desorption is enhanced relative to the parent PA desorption, while styrene formation is dramatically quenched on pre-C-covered (lack of adsorbed hydrogen nearby) surface. It appears that only cross-bridged PA associates with adsorbed hydrogen to form styrene that promptly desorbs at 410 K, while vertically aligned PA is less likely to participate in forming styrene

  13. Using Semantic Similarity In Automated Call Quality Evaluator For Call Centers

    Directory of Open Access Journals (Sweden)

    Ria A. Sagum

    2015-08-01

    Full Text Available Conversation between the agent and client are being evaluated manually by a quality assurance officer QA. This job is only one of the responsibilities being done by a QA and particularly eat ups a lot of time for them which lead to late evaluation results that may cause untimely response of the company to concerns raised by their clients. This research developed an application software that automates and evaluates the quality assurance in business process outsourcing companies or customer service management implementing sentence similarity. The developed system includes two modules speaker diarization which includes transcription and question and answer extraction and similarity checker which checks the similarity between the extracted answer and the answer of the call center agent to a question. The system was evaluated for Correctness of the extracted answers and accurateness of the evaluation for a particular call. Audio conversations were tested for the accuracy of the transcription module which has an accuracy of 27.96. The Precision Recall and F-measure of the extracted answer was tested as 78.03 96.26 and 86.19 respectively. The Accuracy of the system in evaluating a call is 70.

  14. Uranium-mill-tailings remedial-action project (UMTRAP) cover and liner technology development project

    International Nuclear Information System (INIS)

    Hartley, J.N.; Gee, G.W.; Freeman, H.D.; Cline, J.F.; Beedlow, P.A.; Buelt, J.L.; Relyea, J.R.; Tamura, T.

    1982-01-01

    Cover and liner systems for uranium mill tailings in the United States must satisfy stringent requirements regarding long-term stability, radon control, and radionuclide and hazardous chemical migration. The cover placed over a tailings pile serves three basic purposes: (1) to reduce the release of radon, (2) to prevent the intrusion of plant roots and burrowing animals into the tailings, and (3) to limit surface erosion. The liner placed under a tailings pile prevents the migration of radionuclides and hazardous chemicals to groundwater. Pacific Northwest Laboratory is developing and evaluating cover and liner systems that meet these objectives and conform to federal standards. The cover and liner technology discussed in this paper involves: (1) single and multilayer earthen cover systems, (2) asphalt emulsion radon barrier systems, (3) biobarrier systems, (4) revegetation and rock covers, and (5) asphalt, clay, and synthetic liner systems. These systems have been tested at the Grand Junction, Colorado, tailings pile, where they have been shown to effectively reduce radon releases and radionuclide and chemical migration

  15. Investigation of layered covers designed to limit infiltration at waste disposal sites

    International Nuclear Information System (INIS)

    Johnson, T.M.; Herzog, B.L.; Cartwright, K.; Larson, T.H.

    1983-01-01

    Layered soils of highly contrasting texture have been shown to act as a barrier to infiltration because of differences in unsaturated hydraulic properties. Water infiltrating into a fine-grained soil overlying an unsaturated gravel will not enter the gravel until the overlying material is nearly saturated. As a result of what is commonly called the wick effect, moisture will flow laterally through the fine-grained soil above the gravel layer. Layered covers of compacted soil materials utilizing this phenomenon have been proposed to limit infiltration at waste disposal sites. A study funded by the US Nuclear Regulatory Commission is underway to evaluate the potential use of layered trench covers to minimize infiltration at low-level radioactive waste disposal sites. Moisture movement through layered covers consisting of compacted fine-grained soils and sand or gravel was modeled, using a one-dimensional finite-difference model to compare with laboratory column experiments and a two-dimensional finite-element model for field-scale simulations. Soil-moisture characteristic data were obtained from laboratory experiments and the hydraulic conductivity was calculated as a function of capillary pressure. The numerical simulations indicate that layered covers using various combinations of compacted fine-grained soils and coarse-grained material are able to substantially reduce infiltration. Laboratory column experiments using a dual-gamma ray attenuation system to measure moisture content and density simultaneously have been used to observe the behavior of layered soils and to select materials for field testing. Currently underway are field-scale studies of alternative cover designs selected on the basis of two-dimensional modeling

  16. Calling in Work: Secular or Sacred?

    Science.gov (United States)

    Steger, Michael F.; Pickering, N. K.; Shin, J. Y.; Dik, B. J.

    2010-01-01

    Recent scholarship indicates that people who view their work as a calling are more satisfied with their work and their lives. Historically, calling has been regarded as a religious experience, although modern researchers frequently have adopted a more expansive and secular conceptualization of calling, emphasizing meaning and personal fulfillment…

  17. Interaction of cover and target with xenon gas in the IFE-reaction chamber

    International Nuclear Information System (INIS)

    Kuteev, Boris V.

    2001-11-01

    Interaction of a direct drive target and a cover, which is shielding the target against gas particle and heat flows in the reaction chamber of the Inertial Confinement Reactor, is considered. The cover is produced from solid gas -deuterium, neon of xenon. It is shown that at the SOMBRERO parameters the xenon cover with 5.6-mm size significantly reduces the heat flows onto the 4-mm target. The gas drag produces the deceleration of the target much larger than that for the cover due to large mass difference between them. The distance between the target and the cover is about 15 mm at the explosion point, which is sufficient for normal irradiation of the target by laser beams. Protection of the target against the wall radiation is necessary during the flight. Along with creation of reflecting layers over the target surface ablating layers from solid hydrogen or neon seem to be a solution. (author)

  18. Area-averaged evapotranspiration over a heterogeneous land surface: aggregation of multi-point EC flux measurements with a high-resolution land-cover map and footprint analysis

    Directory of Open Access Journals (Sweden)

    F. Xu

    2017-08-01

    Full Text Available The determination of area-averaged evapotranspiration (ET at the satellite pixel scale/model grid scale over a heterogeneous land surface plays a significant role in developing and improving the parameterization schemes of the remote sensing based ET estimation models and general hydro-meteorological models. The Heihe Watershed Allied Telemetry Experimental Research (HiWATER flux matrix provided a unique opportunity to build an aggregation scheme for area-averaged fluxes. On the basis of the HiWATER flux matrix dataset and high-resolution land-cover map, this study focused on estimating the area-averaged ET over a heterogeneous landscape with footprint analysis and multivariate regression. The procedure is as follows. Firstly, quality control and uncertainty estimation for the data of the flux matrix, including 17 eddy-covariance (EC sites and four groups of large-aperture scintillometers (LASs, were carefully done. Secondly, the representativeness of each EC site was quantitatively evaluated; footprint analysis was also performed for each LAS path. Thirdly, based on the high-resolution land-cover map derived from aircraft remote sensing, a flux aggregation method was established combining footprint analysis and multiple-linear regression. Then, the area-averaged sensible heat fluxes obtained from the EC flux matrix were validated by the LAS measurements. Finally, the area-averaged ET of the kernel experimental area of HiWATER was estimated. Compared with the formerly used and rather simple approaches, such as the arithmetic average and area-weighted methods, the present scheme is not only with a much better database, but also has a solid grounding in physics and mathematics in the integration of area-averaged fluxes over a heterogeneous surface. Results from this study, both instantaneous and daily ET at the satellite pixel scale, can be used for the validation of relevant remote sensing models and land surface process models. Furthermore, this

  19. Area-averaged evapotranspiration over a heterogeneous land surface: aggregation of multi-point EC flux measurements with a high-resolution land-cover map and footprint analysis

    Science.gov (United States)

    Xu, Feinan; Wang, Weizhen; Wang, Jiemin; Xu, Ziwei; Qi, Yuan; Wu, Yueru

    2017-08-01

    The determination of area-averaged evapotranspiration (ET) at the satellite pixel scale/model grid scale over a heterogeneous land surface plays a significant role in developing and improving the parameterization schemes of the remote sensing based ET estimation models and general hydro-meteorological models. The Heihe Watershed Allied Telemetry Experimental Research (HiWATER) flux matrix provided a unique opportunity to build an aggregation scheme for area-averaged fluxes. On the basis of the HiWATER flux matrix dataset and high-resolution land-cover map, this study focused on estimating the area-averaged ET over a heterogeneous landscape with footprint analysis and multivariate regression. The procedure is as follows. Firstly, quality control and uncertainty estimation for the data of the flux matrix, including 17 eddy-covariance (EC) sites and four groups of large-aperture scintillometers (LASs), were carefully done. Secondly, the representativeness of each EC site was quantitatively evaluated; footprint analysis was also performed for each LAS path. Thirdly, based on the high-resolution land-cover map derived from aircraft remote sensing, a flux aggregation method was established combining footprint analysis and multiple-linear regression. Then, the area-averaged sensible heat fluxes obtained from the EC flux matrix were validated by the LAS measurements. Finally, the area-averaged ET of the kernel experimental area of HiWATER was estimated. Compared with the formerly used and rather simple approaches, such as the arithmetic average and area-weighted methods, the present scheme is not only with a much better database, but also has a solid grounding in physics and mathematics in the integration of area-averaged fluxes over a heterogeneous surface. Results from this study, both instantaneous and daily ET at the satellite pixel scale, can be used for the validation of relevant remote sensing models and land surface process models. Furthermore, this work will be

  20. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  1. Hornbills can distinguish between primate alarm calls.

    Science.gov (United States)

    Rainey, Hugo J.; Zuberbühler, Klaus; Slater, Peter J. B.

    2004-01-01

    Some mammals distinguish between and respond appropriately to the alarm calls of other mammal and bird species. However, the ability of birds to distinguish between mammal alarm calls has not been investigated. Diana monkeys (Cercopithecus diana) produce different alarm calls to two predators: crowned eagles (Stephanoaetus coronatus) and leopards (Panthera pardus). Yellow-casqued hornbills (Ceratogymna elata) are vulnerable to predation by crowned eagles but are not preyed on by leopards and might therefore be expected to respond to the Diana monkey eagle alarm call but not to the leopard alarm call. We compared responses of hornbills to playback of eagle shrieks, leopard growls, Diana monkey eagle alarm calls and Diana monkey leopard alarm calls and found that they distinguished appropriately between the two predator vocalizations as well as between the two Diana monkey alarm calls. We discuss possible mechanisms leading to these responses. PMID:15209110

  2. Near-field radiative heat transfer between graphene-covered hyperbolic metamaterials

    Science.gov (United States)

    Hong, Xiao-Juan; Li, Jian-Wen; Wang, Tong-Biao; Zhang, De-Jian; Liu, Wen-Xing; Liao, Qing-Hua; Yu, Tian-Bao; Liu, Nian-Hua

    2018-04-01

    We propose the use of graphene-covered silicon carbide (SiC) nanowire arrays (NWAs) for theoretical studies of near-field radiative heat transfer. The SiC NWAs exhibit a hyperbolic characteristic at an appropriately selected filling-volume fraction. The surface plasmon supported by graphene and the hyperbolic modes supported by SiC NWAs significantly affect radiative heat transfer. The heat-transfer coefficient (HTC) between the proposed structures is larger than that between SiC NWAs. We also find that the chemical potential of graphene plays an important role in modulating the HTC. The tunability of chemical potential through gate voltage enables flexible control of heat transfer using the graphene-covered SiC NWAs.

  3. EM wave propagation analysis in plasma covered radar absorbing material

    CERN Document Server

    Singh, Hema; Rawat, Harish Singh

    2017-01-01

    This book focuses on EM propagation characteristics within multilayered plasma-dielectric-metallic media. The method used for analysis is impedance transformation method. Plasma covered radar absorbing material is approximated as a multi-layered dielectric medium. The plasma is considered to be bounded homogeneous/inhomogeneous medium. The reflection coefficient and hence return loss is analytically derived. The role of plasma parameters, such as electron density, collision frequency, plasma thickness, and plasma density profile in the absorption behavior of multi-layered plasma-RAM structure is described. This book provides a clearer picture of EM propagation within plasma. The reader will get an insight of plasma parameters that play significant role in deciding the absorption characteristics of plasma covered surfaces.

  4. Assessing susceptibility to erosion related to land cover changes induced by mining in Anori, Antioquia, Colombia

    International Nuclear Information System (INIS)

    Ceballos Espinosa, Darney de J; Toro R, Luis Jairo

    2012-01-01

    A model for assessing the susceptibility to erosion in the municipality of Anori, through the use of Geographic Information Systems (GIS), was implemented, allowing the spatial assessment of different variables of a model based on the Universal Soil Loss Equation (USLE). Model takes into account possible changes in vegetation cover because of future development of mining projects. The model includes the major hydrological variables such as rain and runoff, as well as slopes, geology and vegetation cover. Anori is located in the north-northeast of Antioquia and presents a valuable mineral potential for the region which has increased thanks to the high prices of gold in the world and the so called mining locomotive driven by the national government. According to the results of this model, the vegetation cover change caused by open pit mining projects directly increases the susceptibility to erosion in Anori. Consequently, environmental management in the erosion susceptibility model is based on the handling of vegetation cover, through the implementation of prevention, mitigation and compensation mechanisms, to avoid increased erosion.

  5. Biological intrusion of low-level-waste trench covers

    International Nuclear Information System (INIS)

    Hakonson, T.E.; Gladney, E.S.

    1981-01-01

    The long-term integrity of low-level waste shallow land burial sites is dependent on the interaction of physical, chemical, and biological factors that modify the waste containment system. Past research on low-level waste shallow land burial methods has emphasized physical (i.e., water infiltration, soil erosion) and chemical (radionuclide leaching) processes that can cause waste site failure and subsequent radionuclide transport. The purpose of this paper is to demonstrate the need to consider biological processes as being potentially important in reducing the integrity of waste burial site cover treatments. Plants and animals not only can transport radionuclides to the ground surface via root systems and soil excavated from the cover profile by animal burrowing activities, but they modify physical and chemical processes within the cover profile by changing the water infiltration rates, soil erosion rates and chemical composition of the soil. One approach to limiting biological intrusion through the waste cover is to apply a barrier within the profile to limit root and animal penetration with depth. Experiments in the Los Alamos Experimental Engineered Test Facility were initiated to develop and evaluate biological barriers that are effective in minimizing intrusion into waste trenches. The experiments that are described employ four different candidate barrier materials of geologic origin. Experimental variables that will be evaluated, in addition to barrier type, are barrier depth and soil overburden depth. The rate of biological intrusion through the various barrier materials is being evaluated through the use of activatable stable tracers

  6. The histological components of the phoniatrical body-cover model in minipigs of different ages.

    Directory of Open Access Journals (Sweden)

    Anja Lang

    Full Text Available Pigs are models in human phoniatry. However, features of maturation and ageing have not been considered with regard to the so-called body-cover model in this species. Therefore, the glottis of "young" (2-3 months; n = 6 and "old" (4-7 years; n = 6 minipigs was investigated. Their cranial (CraF and caudal (CauF vocal folds were histomorphometrically and stratigraphically analysed with emphasis on their amounts of collagen structures and elastic fibres. A dense subepithelial layer (SEL was a distinct feature of CraF and CauF of both age groups; it was spread upon the underlying loose, flexible "cover" like a fibro-elastic membrane. The "cover" was characterised by the so-called superficial layer (SL, which was distinctly loose in the "young" minipigs, but had a much denser texture in the "old" minipigs. Here, the SL was dominated by elastic fibres in the CraF, but was of mixed qualities (collagenous and elastic in the CauF. The structural requirements for the SL's function as a loose "cover" were thus met only in the "young" animals. A clearly demarcated intermediate layer (IL--characterised by high amounts of elastic fibres (as in humans--was only found in the CraF of the "young" animals. In the "old" animals, it had lost its demarcation. In the depth of the CraF of the "old" animals, many thick collagen fibre bundles were detected in a location equivalent to that of the vocal muscle in the CauF. The development of their large diameters was interpreted as part of the maturation process, thereby supporting the hypothesis of their functional importance as a component of the "body." In the CauF, the amounts of collagen structures increased throughout the entire lamina propria, resulting in a loss of demarcated stratigraphical subdivisions in the "old" minipigs. This situation resembled that described in the vocal fold of geriatric humans.

  7. Analysis method for the design of transport packaging shock absorbing end covers

    International Nuclear Information System (INIS)

    Nolan, D.J.; Fernandez, C.; Miller, C.

    1983-01-01

    The analysis method used to design the shock absorbing end covers of the Transnuclear TN-12Y transport packaging is described. The method uses the basic equations of motion (i.e. F = ma) which were programmed for computation with an Apple II computer. Inertia loadings for various positions of the model with respect to the target surface were calculated to determine the worst position to meet the requirements of 10CFR71. For most cover designs evaluated the inertia loading for small angles of inclination at impact with the target surface were larger than for a horizontal position because of the slap-down effect. Different crushable materials were evaluated including the effect of their variation in crushing stress and locking strain. The design was optimized to limit the maximum inertia loadings for the worst impact position to a value of 100 g. 8 references

  8. From nestling calls to fledgling silence: adaptive timing of change in response to aerial alarm calls.

    Science.gov (United States)

    Magrath, Robert D; Platzen, Dirk; Kondo, Junko

    2006-09-22

    Young birds and mammals are extremely vulnerable to predators and so should benefit from responding to parental alarm calls warning of danger. However, young often respond differently from adults. This difference may reflect: (i) an imperfect stage in the gradual development of adult behaviour or (ii) an adaptation to different vulnerability. Altricial birds provide an excellent model to test for adaptive changes with age in response to alarm calls, because fledglings are vulnerable to a different range of predators than nestlings. For example, a flying hawk is irrelevant to a nestling in a enclosed nest, but is dangerous to that individual once it has left the nest, so we predict that young develop a response to aerial alarm calls to coincide with fledging. Supporting our prediction, recently fledged white-browed scrubwrens, Sericornis frontalis, fell silent immediately after playback of their parents' aerial alarm call, whereas nestlings continued to calling despite hearing the playback. Young scrubwrens are therefore exquisitely adapted to the changing risks faced during development.

  9. Staffing to Maximize Profit for Call Centers with Impatient and Repeat-Calling Customers

    Directory of Open Access Journals (Sweden)

    Jun Gong

    2015-01-01

    Full Text Available Motivated by call center practice, we study the optimal staffing of many-server queues with impatient and repeat-calling customers. A call center is modeled as an M/M/s+M queue, which is developed to a behavioral queuing model in which customers come and go based on their satisfaction with waiting time. We explicitly take into account customer repeat behavior, which implies that satisfied customers might return and have an impact on the arrival rate. Optimality is defined as the number of agents that maximize revenues net of staffing costs, and we account for the characteristic that revenues are a direct function of staffing. Finally, we use numerical experiments to make certain comparisons with traditional models that do not consider customer repeat behavior. Furthermore, we indicate how managers might allocate staffing optimally with various customer behavior mechanisms.

  10. Atmospheric volatilization and distribution of (Z)- and (E)-1,3-dichloropropene in field beds with and without plastic covers.

    Science.gov (United States)

    Thomas, John E; Allen, L Hartwell; McCormack, Leslie A; Vu, Joseph C; Dickson, Donald W; Ou, Li-Tse

    2004-01-01

    The fumigant 1,3-dichloropropene (1,3-D) is considered to be a potential replacement for methyl bromide when methyl bromide is phased out in 2005. This study on surface emissions and subsurface diffusion of 1,3-D in a Florida sandy soil was conducted in field beds with or without plastic covers. After injection of the commercial fumigant Telone II by conventional chisels to field beds at 30cm depth which were covered with polyethylene film (PE), virtually impermeable film, or no cover (bare), (Z)- and (E)-1,3-D rapidly diffused upward. Twenty hours after injection, majority of (Z)- and (E)-1,3-D had moved upward from 30 cm depth to the layer of 5-20 cm depth. Downward movement of the two isomers in the beds with or without a plastic cover was not significant. (Z)-1,3-D diffused more rapidly than (E)-1,3-D. Virtually impermeable films (VIF) had a good capacity to retain (Z)- and (E)-1,3-D in soil pore air space. Vapor concentrations of the two isomers in the shallow subsurface of the field bed covered with VIF were greater than that in the two beds covered with polyethylene film (PE) or no cover (bare). In addition, VIF cover provided more uniform distribution of (Z)- and (E)-1,3-D in shallow subsurface than PE cover or no cover. Virtually impermeable film also had a better capability to retard surface emissions of the two isomers from soil in field beds than PE cover or no cover.

  11. Electron emission from MOS electron emitters with clean and cesium covered gold surface

    DEFF Research Database (Denmark)

    Nielsen, Gunver; Thomsen, Lasse Bjørchmar; Johansson, Martin

    2009-01-01

    MOS (metal-oxide-semiconductor) electron emitters consisting of a Si substrate, a SiO2 tunnel barrier and a Ti (1 nm)/Au(7 nm) top-electrode, with an active area of 1 cm(2) have been produced and studied with surface science techniques under UHV (ultra high vacuum) conditions and their emission...... characteristics have been investigated. It is known, that deposition of an alkali metal on the emitting surface lowers the work function and increases the emission efficiency. For increasing Cs coverages the surface has been characterized by X-ray Photoelectron Spectroscopy (XPS), Ion Scattering Spectroscopy (ISS...

  12. The efficiency of a lead covering for X-ray examination of the pelvis

    International Nuclear Information System (INIS)

    Kainberger, F.; Kallinger, W.; Hofer, H.

    1979-01-01

    This is a report on the protective covering of the infant's pelvis. Comparative measurements of two customary lead covers, phantom measurements and comparative measurements on infants were carried out. Results show that a properly applied lead cover with a correct lead value (at least the equivalent of 1 mm of lead) may be considered a very effective protection against irradiation, a method that reduces irradiation to the gonads by a factor of 100. The initial dosis is at the surface and, as a rule, is below 1 mR. The dosis attaching the gonads is most likely within the micro-R-range. Thus we state for practical purposes that a lead protective cover is very effective in X-raying the infant pelvis - indeed it should be mandatory for every pelvic X-ray taken of infants. (author)

  13. ABOUT THE GEOMETRY AND THE APPLICATIONS OF THE TWISTED SURFACES

    Directory of Open Access Journals (Sweden)

    MÂRZA Carmen

    2015-06-01

    Full Text Available The helical and spiral surfaces are used in various fields. These surfaces are obtained by rotating a segment line called generatrix around directrices lines, respectively the spiral surfaces are obtained by composing simultaneously the movements of translation and rotation of a plane figure around an axis - which can be a straight line or a curved line, or around a real or imaginary surface - called core. After an overview of these surfaces, the attention of the authors will be focused on the geometrical and graphical analysis of the twisted surfaces in civil engineering branch, such as: columns, helical ramps and stairs, respectively buildings having a futuristic design.

  14. Estimation of surface air temperature over central and eastern Eurasia from MODIS land surface temperature

    International Nuclear Information System (INIS)

    Shen Suhung; Leptoukh, Gregory G

    2011-01-01

    Surface air temperature (T a ) is a critical variable in the energy and water cycle of the Earth–atmosphere system and is a key input element for hydrology and land surface models. This is a preliminary study to evaluate estimation of T a from satellite remotely sensed land surface temperature (T s ) by using MODIS-Terra data over two Eurasia regions: northern China and fUSSR. High correlations are observed in both regions between station-measured T a and MODIS T s . The relationships between the maximum T a and daytime T s depend significantly on land cover types, but the minimum T a and nighttime T s have little dependence on the land cover types. The largest difference between maximum T a and daytime T s appears over the barren and sparsely vegetated area during the summer time. Using a linear regression method, the daily maximum T a were estimated from 1 km resolution MODIS T s under clear-sky conditions with coefficients calculated based on land cover types, while the minimum T a were estimated without considering land cover types. The uncertainty, mean absolute error (MAE), of the estimated maximum T a varies from 2.4 °C over closed shrublands to 3.2 °C over grasslands, and the MAE of the estimated minimum T a is about 3.0 °C.

  15. Enhancing the representation of subgrid land surface characteristics in land surface models

    Directory of Open Access Journals (Sweden)

    Y. Ke

    2013-09-01

    Full Text Available Land surface heterogeneity has long been recognized as important to represent in the land surface models. In most existing land surface models, the spatial variability of surface cover is represented as subgrid composition of multiple surface cover types, although subgrid topography also has major controls on surface processes. In this study, we developed a new subgrid classification method (SGC that accounts for variability of both topography and vegetation cover. Each model grid cell was represented with a variable number of elevation classes and each elevation class was further described by a variable number of vegetation types optimized for each model grid given a predetermined total number of land response units (LRUs. The subgrid structure of the Community Land Model (CLM was used to illustrate the newly developed method in this study. Although the new method increases the computational burden in the model simulation compared to the CLM subgrid vegetation representation, it greatly reduced the variations of elevation within each subgrid class and is able to explain at least 80% of the total subgrid plant functional types (PFTs. The new method was also evaluated against two other subgrid methods (SGC1 and SGC2 that assigned fixed numbers of elevation and vegetation classes for each model grid (SGC1: M elevation bands–N PFTs method; SGC2: N PFTs–M elevation bands method. Implemented at five model resolutions (0.1°, 0.25°, 0.5°, 1.0°and 2.0° with three maximum-allowed total number of LRUs (i.e., NLRU of 24, 18 and 12 over North America (NA, the new method yielded more computationally efficient subgrid representation compared to SGC1 and SGC2, particularly at coarser model resolutions and moderate computational intensity (NLRU = 18. It also explained the most PFTs and elevation variability that is more homogeneously distributed spatially. The SGC method will be implemented in CLM over the NA continent to assess its impacts on

  16. Gross and net land cover changes in the main plant functional types derived from the annual ESA CCI land cover maps (1992-2015)

    Science.gov (United States)

    Li, Wei; MacBean, Natasha; Ciais, Philippe; Defourny, Pierre; Lamarche, Céline; Bontemps, Sophie; Houghton, Richard A.; Peng, Shushi

    2018-01-01

    Land-use and land-cover change (LULCC) impacts local energy and water balance and contributes on global scale to a net carbon emission to the atmosphere. The newly released annual ESA CCI (climate change initiative) land cover maps provide continuous land cover changes at 300 m resolution from 1992 to 2015, and can be used in land surface models (LSMs) to simulate LULCC effects on carbon stocks and on surface energy budgets. Here we investigate the absolute areas and gross and net changes in different plant functional types (PFTs) derived from ESA CCI products. The results are compared with other datasets. Global areas of forest, cropland and grassland PFTs from ESA are 30.4, 19.3 and 35.7 million km2 in the year 2000. The global forest area is lower than that from LUH2v2h (Hurtt et al., 2011), Hansen et al. (2013) or Houghton and Nassikas (2017) while cropland area is higher than LUH2v2h (Hurtt et al., 2011), in which cropland area is from HYDE 3.2 (Klein Goldewijk et al., 2016). Gross forest loss and gain during 1992-2015 are 1.5 and 0.9 million km2 respectively, resulting in a net forest loss of 0.6 million km2, mainly occurring in South and Central America. The magnitudes of gross changes in forest, cropland and grassland PFTs in the ESA CCI are smaller than those in other datasets. The magnitude of global net cropland gain for the whole period is consistent with HYDE 3.2 (Klein Goldewijk et al., 2016), but most of the increases happened before 2004 in ESA and after 2007 in HYDE 3.2. Brazil, Bolivia and Indonesia are the countries with the largest net forest loss from 1992 to 2015, and the decreased areas are generally consistent with those from Hansen et al. (2013) based on Landsat 30 m resolution images. Despite discrepancies compared to other datasets, and uncertainties in converting into PFTs, the new ESA CCI products provide the first detailed long-term time series of land-cover change and can be implemented in LSMs to characterize recent carbon dynamics

  17. Control of single-electron charging of metallic nanoparticles onto amorphous silicon surface.

    Science.gov (United States)

    Weis, Martin; Gmucová, Katarína; Nádazdy, Vojtech; Capek, Ignác; Satka, Alexander; Kopáni, Martin; Cirák, Július; Majková, Eva

    2008-11-01

    Sequential single-electron charging of iron oxide nanoparticles encapsulated in oleic acid/oleyl amine envelope and deposited by the Langmuir-Blodgett technique onto Pt electrode covered with undoped hydrogenated amorphous silicon film is reported. Single-electron charging (so-called quantized double-layer charging) of nanoparticles is detected by cyclic voltammetry as current peaks and the charging effect can be switched on/off by the electric field in the surface region induced by the excess of negative/positive charged defect states in the amorphous silicon layer. The particular charge states in amorphous silicon are created by the simultaneous application of a suitable bias voltage and illumination before the measurement. The influence of charged states on the electric field in the surface region is evaluated by the finite element method. The single-electron charging is analyzed by the standard quantized double layer model as well as two weak-link junctions model. Both approaches are in accordance with experiment and confirm single-electron charging by tunnelling process at room temperature. This experiment illustrates the possibility of the creation of a voltage-controlled capacitor for nanotechnology.

  18. Optimal land use/land cover classification using remote sensing imagery for hydrological modeling in a Himalayan watersched

    NARCIS (Netherlands)

    Saran, S.; Sterk, G.; Kumar, S.

    2009-01-01

    Land use/land cover is an important watershed surface characteristic that affects surface runoff and erosion. Many of the available hydrological models divide the watershed into Hydrological Response Units (HRU), which are spatial units with expected similar hydrological behaviours. The division

  19. Surface science an introduction

    CERN Document Server

    Hudson, John

    1991-01-01

    The whole field of surface science is covered in this work. Starting with a description of the structure and thermodynamics of clean surfaces, the book goes on to discuss kinetic theory of gases and molecular beam formation. This is followed by a largesection on gas-surface interactions, and another major section on energetic particle-surface interactions. The final chapter provides the background to crystal nucleation and growth. The approach adopted is interdisciplinary and slanted towards theexperimental side, with practical analytical techniques being used to illustrate general princi

  20. Peafowl antipredator calls encode information about signalers.

    Science.gov (United States)

    Yorzinski, Jessica L

    2014-02-01

    Animals emit vocalizations that convey information about external events. Many of these vocalizations, including those emitted in response to predators, also encode information about the individual that produced the call. The relationship between acoustic features of antipredator calls and information relating to signalers (including sex, identity, body size, and social rank) were examined in peafowl (Pavo cristatus). The "bu-girk" antipredator calls of male and female peafowl were recorded and 20 acoustic parameters were automatically extracted from each call. Both the bu and girk elements of the antipredator call were individually distinctive and calls were classified to the correct signaler with over 90% and 70% accuracy in females and males, respectively. Females produced calls with a higher fundamental frequency (F0) than males. In both females and males, body size was negatively correlated with F0. In addition, peahen rank was related to the duration, end mean frequency, and start harmonicity of the bu element. Peafowl antipredator calls contain detailed information about the signaler and can potentially be used by receivers to respond to dangerous situations.

  1. Ferromanganese nodule fauna in the Tropical North Pacific Ocean: Species richness, faunal cover and spatial distribution

    Science.gov (United States)

    Veillette, Julie; Sarrazin, Jozée; Gooday, Andrew J.; Galéron, Joëlle; Caprais, Jean-Claude; Vangriesheim, Annick; Étoubleau, Joël; Christian, James R.; Kim Juniper, S.

    2007-11-01

    The poorly known ferromanganese nodule fauna is a widespread hard substratum community in the deep sea that will be considerably impacted by large-scale nodule mining operations. The objective of this study was to analyze the spatial distribution of the fauna attached to nodules in the Clarion-Clipperton Fracture Zone at two scales; a regional scale that includes the east (14°N, 130°W) and the west (9°N, 150°W) zones and a local scale in which different geological facies (A, B, C and west) are recognizable. The fauna associated with 235 nodules was quantitatively described: 104 nodules from the east zone (15 of facies A, 50 of facies B and 39 of facies C) and 131 nodules from the west zone. Percent cover was used to quantify the extent of colonization at the time of sampling, for 42 species out of the 62 live species observed. Fauna covered up to 18% of exposed nodule surface with an average of about 3%. While species richness increased with exposed nodule surface, both at the regional and at the facies scales (except for facies A), total species density decreased (again except for facies A). When all nodules were included in the statistical analysis, there was no relation between faunal cover and exposed nodule surface. Nevertheless, faunal cover did decrease with exposed nodule surface for the east zone in general and for both facies B and C in particular. Species distributions among facies were significantly different but explained only a very small portion of the variance (˜5%). We identified two groups of associated species: a first group of two species and a second group of six species. The other species (34) were independently distributed, suggesting that species interactions play only a minor role in the spatial distribution of nodule fauna. The flux of particulate organic carbon to the bottom is the only major environmental factor considered to vary between the two zones within this study. We conclude that the higher species richness and higher

  2. Control of water infiltration into near surface LLW disposal units: Progress report on field experiments at a humid region site, Beltsville, Maryland

    International Nuclear Information System (INIS)

    Schulz, R.K.; Ridky, R.W.

    1996-08-01

    This study's objective is to assess means for controlling water infiltration through waste disposal unit covers in humid regions. Experimental work is being performed in large-scale lysimeters 21.34 m x 13.72 m x 3.05 m (70 ft x 45 ft x 10 ft) at Beltsville, Maryland. Results of the assessment are applicable to disposal of low-level radioactive waste (LLW), uranium mill tailings, hazardous waste, and sanitary landfills. Three kinds of waste disposal unit covers or barriers to water infiltration are being investigated: (1) resistive layer barrier, (2) conductive layer barrier, and (3) bioengineering management. The resistive layer barrier consists of compacted earthen material (e.g., clay). The conductive layer barrier consists of a conductive layer in conjunction with a capillary break. As long as unsaturated flow conditions are maintained, the conductive layer will wick water around the capillary break. Below-grade layered covers such as (1) and (2) will fail if there is appreciable subsidence of the cover, and remedial action for this kind of failure will be difficult. A surface cover, called bioengineering management, is meant to overcome this problem. The bioengineering management surface barrier is easily repairable if damaged by subsidence; therefore, it could be the system of choice under active subsidence conditions. The bioengineering management procedure also has been shown to be effective in dewatering saturated trenches and could be used for remedial action efforts. After cessation of subsidence, that procedure could be replaced by a resistive layer barrier or, perhaps even better, by a resistive layer barrier/conductive layer barrier system. The latter system would then give long-term effective protection against water entry into waste without institutional care

  3. Thermographic analysis of plasma facing components covered by carbon surface layer in tokamaks

    International Nuclear Information System (INIS)

    Gardarein, Jean-Laurent

    2007-01-01

    Tokamaks are reactors based on the thermonuclear fusion energy with magnetic confinement of the plasma. In theses machines, several MW are coupled to the plasma for about 10 s. A large part of this power is directed towards plasma facing components (PFC). For better understanding and control the heat flux transfer from the plasma to the surrounding wall, it is very important to measure the surface temperature of the PFC and to estimate the imposed heat flux. In most of tokamaks using carbon PFC, the eroded carbon is circulating in the plasma and redeposited elsewhere. During the plasma operations, this leads at some locations to the formation of thin or thick carbon layers usually poorly attached to the PFC. These surface layers with unknown thermal properties complicate the calculation of the heat flux from IR surface temperature measurements. To solve this problem, we develop first, inverse method to estimate the heat flux using thermocouple (not sensitive to the carbon surface layers) temperature measurements. Then, we propose a front face pulsed photothermal method allowing an estimation of layers thermal diffusivity, conductivity, effusivity and the thermal contact resistance between the layer and the tile. The principle is to study with an infrared sensor, the cooling of the layer surface after heating by a short laser pulse, this cooling depending on the thermal properties of the successive layers. (author) [fr

  4. BUFO PARDALIS (ANURA: BUFONIDAE): MATING CALL AND ...

    African Journals Online (AJOL)

    the calls of one of these species, Bufo pardalis. Hewitt, were not analysed by Tandy & Keith. (1972). Furthennore there is some confusion in the literature regarding the mating call of this species. For these reasons this mating call is here clarified. The mating call of B. pardaiis was first described by Ranger (in Hewitt 1935) as ...

  5. Impact of mobility on call block, call drops and optimal cell size in small cell networks

    OpenAIRE

    Ramanath , Sreenath; Voleti , Veeraruna Kavitha; Altman , Eitan

    2011-01-01

    We consider small cell networks and study the impact of user mobility. Assuming Poisson call arrivals at random positions with random velocities, we discuss the characterization of handovers at the boundaries. We derive explicit expressions for call block and call drop probabilities using tools from spatial queuing theory. We also derive expressions for the average virtual server held up time. These expressions are used to derive optimal cell sizes for various profile of velocities in small c...

  6. A Comparison of Advanced Regression Algorithms for Quantifying Urban Land Cover

    Directory of Open Access Journals (Sweden)

    Akpona Okujeni

    2014-07-01

    Full Text Available Quantitative methods for mapping sub-pixel land cover fractions are gaining increasing attention, particularly with regard to upcoming hyperspectral satellite missions. We evaluated five advanced regression algorithms combined with synthetically mixed training data for quantifying urban land cover from HyMap data at 3.6 and 9 m spatial resolution. Methods included support vector regression (SVR, kernel ridge regression (KRR, artificial neural networks (NN, random forest regression (RFR and partial least squares regression (PLSR. Our experiments demonstrate that both kernel methods SVR and KRR yield high accuracies for mapping complex urban surface types, i.e., rooftops, pavements, grass- and tree-covered areas. SVR and KRR models proved to be stable with regard to the spatial and spectral differences between both images and effectively utilized the higher complexity of the synthetic training mixtures for improving estimates for coarser resolution data. Observed deficiencies mainly relate to known problems arising from spectral similarities or shadowing. The remaining regressors either revealed erratic (NN or limited (RFR and PLSR performances when comprehensively mapping urban land cover. Our findings suggest that the combination of kernel-based regression methods, such as SVR and KRR, with synthetically mixed training data is well suited for quantifying urban land cover from imaging spectrometer data at multiple scales.

  7. [Process study on hysteresis of vegetation cover influencing sand-dust events].

    Science.gov (United States)

    Xu, Xing-Kui; Wang, Xiao-Tao; Zhang, Feng

    2009-02-15

    Data analysis from satellite and weather stations during 1982-2000 shows nonlinear relationship between vegetation cover and sand-dust events is present in most part of China. Vegetation cover ratio in summer can impact significantly on the frequency of sand-dust storms from winter to spring in the source regions of sand-dust events. It is not quite clear about the hysteresis that vegetation cover in summer influence sand-dust events during winter and spring. A quasi-geostrophic barotropic model is used under the condition of 3 magnitude of frictional coefficient to investigate the cause of the hysteresis. Wind velocity shows a greatest decline at 90% during 72 h as initial wind velocity is 10 m/s for magnitude of frictional coefficient between atmosphere and water surface, greatest decline at 100% during 18 h for magnitude of frictional coefficient between atmosphere and bare soil and a 100% reduction of wind speed during 1 h for magnitude of frictional coefficient between atmosphere and vegetation cover. Observation and simulation prove that residual root and stem from summervegetation are one of factors to influence sand-dust events happened during winter and spring. Air inhibition from residual root and stem is a most important reason for hysteresis that vegetation cover influence sand-dust events.

  8. Resistance of biofilm-covered mortars to microbiologically influenced deterioration simulated by sulfuric acid exposure

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani, Sahar, E-mail: ssoleima@connect.carleton.ca; Isgor, O. Burkan, E-mail: burkan_isgor@carleton.ca; Ormeci, Banu, E-mail: banu_ormeci@carleton.ca

    2013-11-15

    Following the reported success of biofilm applications on metal surfaces to inhibit microbiologically influenced corrosion, effectiveness and sustainability of E. coli DH5α biofilm on mortar surface to prevent microbiologically influenced concrete deterioration (MICD) are investigated. Experiments simulating microbial attack were carried out by exposing incrementally biofilm-covered mortar specimens to sulfuric acid solutions with pH ranging from 3 to 6. Results showed that calcium concentration in control reactors without biofilm was 23–47% higher than the reactors with biofilm-covered mortar. Formation of amorphous silica gel as an indication of early stages of acid attack was observed only on the control mortar specimens without biofilm. During acidification, the biofilm continued to grow and its thickness almost doubled from ∼ 30 μm before acidification to ∼ 60 μm after acidification. These results demonstrated that E. coli DH5α biofilm was able to provide a protective and sustainable barrier on mortar surfaces against medium to strong sulfuric acid attack. -- Highlights: •Effectiveness of E.coli DH5α biofilm to prevent MICD was studied. •Conditions that lead to MICD were simulated by chemical acidification. •Biofilm-covered mortar specimens were exposed to sulfuric acid solutions. •The presence of biofilm helped reduce the chemically-induced mortar deterioration. •Biofilm remained alive and continued to grow during the acidification process.

  9. Resistance of biofilm-covered mortars to microbiologically influenced deterioration simulated by sulfuric acid exposure

    International Nuclear Information System (INIS)

    Soleimani, Sahar; Isgor, O. Burkan; Ormeci, Banu

    2013-01-01

    Following the reported success of biofilm applications on metal surfaces to inhibit microbiologically influenced corrosion, effectiveness and sustainability of E. coli DH5α biofilm on mortar surface to prevent microbiologically influenced concrete deterioration (MICD) are investigated. Experiments simulating microbial attack were carried out by exposing incrementally biofilm-covered mortar specimens to sulfuric acid solutions with pH ranging from 3 to 6. Results showed that calcium concentration in control reactors without biofilm was 23–47% higher than the reactors with biofilm-covered mortar. Formation of amorphous silica gel as an indication of early stages of acid attack was observed only on the control mortar specimens without biofilm. During acidification, the biofilm continued to grow and its thickness almost doubled from ∼ 30 μm before acidification to ∼ 60 μm after acidification. These results demonstrated that E. coli DH5α biofilm was able to provide a protective and sustainable barrier on mortar surfaces against medium to strong sulfuric acid attack. -- Highlights: •Effectiveness of E.coli DH5α biofilm to prevent MICD was studied. •Conditions that lead to MICD were simulated by chemical acidification. •Biofilm-covered mortar specimens were exposed to sulfuric acid solutions. •The presence of biofilm helped reduce the chemically-induced mortar deterioration. •Biofilm remained alive and continued to grow during the acidification process

  10. Image-based overlay and alignment metrology through optically opaque media with sub-surface probe microscopy

    Science.gov (United States)

    van Es, Maarten H.; Mohtashami, Abbas; Piras, Daniele; Sadeghian, Hamed

    2018-03-01

    Nondestructive subsurface nanoimaging through optically opaque media is considered to be extremely challenging and is essential for several semiconductor metrology applications including overlay and alignment and buried void and defect characterization. The current key challenge in overlay and alignment is the measurement of targets that are covered by optically opaque layers. Moreover, with the device dimensions moving to the smaller nodes and the issue of the so-called loading effect causing offsets between between targets and product features, it is increasingly desirable to perform alignment and overlay on product features or so-called on-cell overlay, which requires higher lateral resolution than optical methods can provide. Our recently developed technique known as SubSurface Ultrasonic Resonance Force Microscopy (SSURFM) has shown the capability for high-resolution imaging of structures below a surface based on (visco-)elasticity of the constituent materials and as such is a promising technique to perform overlay and alignment with high resolution in upcoming production nodes. In this paper, we describe the developed SSURFM technique and the experimental results on imaging buried features through various layers and the ability to detect objects with resolution below 10 nm. In summary, the experimental results show that the SSURFM is a potential solution for on-cell overlay and alignment as well as detecting buried defects or voids and generally metrology through optically opaque layers.

  11. Analysis of Stable Isotope Contents of Surface and Underground ...

    African Journals Online (AJOL)

    Sam Eshun

    (2H/1H) ratios relative to a standard called Standard Mean Ocean Water (SMOW) ..... Hence, higher forest cover has greater influence on heavy isotope ... Accra Plains is influenced by the Atlantic Ocean where the relative humidity is higher ...

  12. Variability and Anomalous Trends in the Global Sea Ice Cover

    Science.gov (United States)

    Comiso, Josefino C.

    2012-01-01

    MODIS, AMSR-E and SSM/I data reveal that the sea ice production rate at the coastal polynyas along the Ross Ice Shelf has been increasing since 1992. This also means that the salinization rate and the formation of bottom water in the region are going up as well. Simulation studies indicate that the stronger production rate is likely associated with the ozone hole that has caused a deepening of the lows in the West Antarctic region and therefore stronger winds off the Ross Ice Shelf. Stronger winds causes larger coastal polynyas near the shelf and hence an enhanced ice production in the region during the autumn and winter period. Results of analysis of temperature data from MODIS and AMSR-E shows that the area and concentration of the sea ice cover are highly correlated with surface temperature for both the Arctic and Antarctic, especially in the seasonal regions where the correlation coefficients are about 0.9. Abnormally high sea surface temperatures (SSTs) and surface ice temperatures (SITs) were also observed in 2007 and 2011when drastic reductions in the summer ice cover occurred, This phenomenon is consistent with the expected warming of the upper layer of the Arctic Ocean on account of ice-albedo feedback. Changes in atmospheric circulation are also expected to have a strong influence on the sea ice cover but the results of direct correlation analyses of the sea ice cover with the Northern and the Southern Annular Mode indices show relatively weak correlations, This might be due in part to the complexity of the dynamics of the system that can be further altered by some phenomena like the Antarctic Circumpolar Wave and extra polar processes like the El Nino Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (POD),

  13. The DTU15 MSS (Mean Sea Surface) and DTU15LAT (Lowest Astronomical Tide) reference surface

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Stenseng, Lars; Piccioni, Gaia

    in the Arctic Ocean for DTU10MSS and DTU13MSS.A new reference surface for off-shore vertical referencing is introduced. This is called the DTU15LAT.The surface is derived from the DTU15MSS and the DTU10 Global ocean tide to give a 19 year Lowest Astronomical Tide referenced to either the Mean sea surface...

  14. The response of Arctic vegetation to the summer climate: relation between shrub cover, NDVI, surface albedo and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Blok, Daan; Heijmans, Monique M P D; Berendse, Frank [Nature Conservation and Plant Ecology Group, Wageningen University, PO Box 47, 6700 AA, Wageningen (Netherlands); Schaepman-Strub, Gabriela [Institute of Evolutionary Biology and Environmental Studies, University of Zuerich, Winterthurerstrasse 190, 8057 Zuerich (Switzerland); Bartholomeus, Harm [Centre for Geo-Information, Wageningen University, PO Box 47, 6700 AA, Wageningen (Netherlands); Maximov, Trofim C, E-mail: daan.blok@wur.nl [Biological Problems of the Cryolithozone, Russian Academy of Sciences, Siberian Division, 41, Lenin Prospekt, Yakutsk, The Republic of Sakha, Yakutia 677980 (Russian Federation)

    2011-07-15

    Recently observed Arctic greening trends from normalized difference vegetation index (NDVI) data suggest that shrub growth is increasing in response to increasing summer temperature. An increase in shrub cover is expected to decrease summer albedo and thus positively feed back to climate warming. However, it is unknown how albedo and NDVI are affected by shrub cover and inter-annual variations in the summer climate. Here, we examine the relationship between deciduous shrub fractional cover, NDVI and albedo using field data collected at a tundra site in NE Siberia. Field data showed that NDVI increased and albedo decreased with increasing deciduous shrub cover. We then selected four Arctic tundra study areas and compiled annual growing season maximum NDVI and minimum albedo maps from MODIS satellite data (2000-10) and related these satellite products to tundra vegetation types (shrub, graminoid, barren and wetland tundra) and regional summer temperature. We observed that maximum NDVI was greatest in shrub tundra and that inter-annual variation was negatively related to summer minimum albedo but showed no consistent relationship with summer temperature. Shrub tundra showed higher albedo than wetland and barren tundra in all four study areas. These results suggest that a northwards shift of shrub tundra might not lead to a decrease in summer minimum albedo during the snow-free season when replacing wetland tundra. A fully integrative study is however needed to link results from satellite data with in situ observations across the Arctic to test the effect of increasing shrub cover on summer albedo in different tundra vegetation types.

  15. The response of Arctic vegetation to the summer climate: relation between shrub cover, NDVI, surface albedo and temperature

    International Nuclear Information System (INIS)

    Blok, Daan; Heijmans, Monique M P D; Berendse, Frank; Schaepman-Strub, Gabriela; Bartholomeus, Harm; Maximov, Trofim C

    2011-01-01

    Recently observed Arctic greening trends from normalized difference vegetation index (NDVI) data suggest that shrub growth is increasing in response to increasing summer temperature. An increase in shrub cover is expected to decrease summer albedo and thus positively feed back to climate warming. However, it is unknown how albedo and NDVI are affected by shrub cover and inter-annual variations in the summer climate. Here, we examine the relationship between deciduous shrub fractional cover, NDVI and albedo using field data collected at a tundra site in NE Siberia. Field data showed that NDVI increased and albedo decreased with increasing deciduous shrub cover. We then selected four Arctic tundra study areas and compiled annual growing season maximum NDVI and minimum albedo maps from MODIS satellite data (2000-10) and related these satellite products to tundra vegetation types (shrub, graminoid, barren and wetland tundra) and regional summer temperature. We observed that maximum NDVI was greatest in shrub tundra and that inter-annual variation was negatively related to summer minimum albedo but showed no consistent relationship with summer temperature. Shrub tundra showed higher albedo than wetland and barren tundra in all four study areas. These results suggest that a northwards shift of shrub tundra might not lead to a decrease in summer minimum albedo during the snow-free season when replacing wetland tundra. A fully integrative study is however needed to link results from satellite data with in situ observations across the Arctic to test the effect of increasing shrub cover on summer albedo in different tundra vegetation types.

  16. Assessing the Impact of Land Use and Land Cover Change on Global Water Resources

    Science.gov (United States)

    Batra, N.; Yang, Y. E.; Choi, H. I.; Islam, A.; Charlotte, D. F.; Cai, X.; Kumar, P.

    2007-12-01

    Land use and land cover changes (LULCC) significantly modify the hydrological regime of the watersheds, affecting water resources and environment from regional to global scale. This study seeks to advance and integrate water and energy cycle observation, scientific understanding, and human impacts to assess future water availability. To achieve the research objective, we integrate and interpret past and current space based and in situ observations into a global hydrologic model (GHM). GHM is developed with enhanced spatial and temporal resolution, physical complexity, hydrologic theory and processes to quantify the impact of LULCC on physical variables: surface runoff, subsurface flow, groundwater, infiltration, ET, soil moisture, etc. Coupled with the common land model (CLM), a 3-dimensional volume averaged soil-moisture transport (VAST) model is expanded to incorporate the lateral flow and subgrid heterogeneity. The model consists of 11 soil-hydrology layers to predict lateral as well as vertical moisture flux transport based on Richard's equations. The primary surface boundary conditions (SBCs) include surface elevation and its derivatives, land cover category, sand and clay fraction profiles, bedrock depth and fractional vegetation cover. A consistent global GIS-based dataset is constructed for the SBCs of the model from existing observational datasets comprising of various resolutions, map projections and data formats. Global ECMWF data at 6-hour time steps for the period 1971 through 2000 is processed to get the forcing data which includes incoming longwave and shortwave radiation, precipitation, air temperature, pressure, wind components, boundary layer height and specific humidity. Land use land cover data, generated using IPCC scenarios for every 10 years from 2000 to 2100 is used for future assessment on water resources. Alterations due to LULCC on surface water balance components: ET, groundwater recharge and runoff are then addressed in the study. Land

  17. Representing the effects of alpine grassland vegetation cover on the simulation of soil thermal dynamics by ecosystem models applied to the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Yi, S.; Li, N.; Xiang, B.; Wang, X.; Ye, B.; McGuire, A.D.

    2013-01-01

    Soil surface temperature is a critical boundary condition for the simulation of soil temperature by environmental models. It is influenced by atmospheric and soil conditions and by vegetation cover. In sophisticated land surface models, it is simulated iteratively by solving surface energy budget equations. In ecosystem, permafrost, and hydrology models, the consideration of soil surface temperature is generally simple. In this study, we developed a methodology for representing the effects of vegetation cover and atmospheric factors on the estimation of soil surface temperature for alpine grassland ecosystems on the Qinghai-Tibetan Plateau. Our approach integrated measurements from meteorological stations with simulations from a sophisticated land surface model to develop an equation set for estimating soil surface temperature. After implementing this equation set into an ecosystem model and evaluating the performance of the ecosystem model in simulating soil temperature at different depths in the soil profile, we applied the model to simulate interactions among vegetation cover, freeze-thaw cycles, and soil erosion to demonstrate potential applications made possible through the implementation of the methodology developed in this study. Results showed that (1) to properly estimate daily soil surface temperature, algorithms should use air temperature, downward solar radiation, and vegetation cover as independent variables; (2) the equation set developed in this study performed better than soil surface temperature algorithms used in other models; and (3) the ecosystem model performed well in simulating soil temperature throughout the soil profile using the equation set developed in this study. Our application of the model indicates that the representation in ecosystem models of the effects of vegetation cover on the simulation of soil thermal dynamics has the potential to substantially improve our understanding of the vulnerability of alpine grassland ecosystems to

  18. Mean species cover: a harmonized indicator of shrub cover for forest inventories

    Science.gov (United States)

    Iciar Alberdi; Sonia Condés; Ronald E. Mcroberts; Susanne Winter

    2018-01-01

    Because shrub cover is related to many forest ecosystem functions, it is one of the most relevant variables for describing these communities. Nevertheless, a harmonized indicator of shrub cover for large-scale reporting is lacking. The aims of the study were threefold: to define a shrub indicator that can be used by European countries for harmonized shrub cover...

  19. Effects of various tailings covers on radon gas emanation from pyritic uranium tailings

    International Nuclear Information System (INIS)

    Dave, N.K.; Lim, T.P.

    1987-01-01

    Radon emanation studies were carried out at an inactive pyritic uranium tailings site in Elliot Lake, Ontario, Canada, to evaluate the effects of various existing dry and wet covers on radon flux rates. Measurements were taken using activated charcoal cartridges for various surface covers consisting of bare, vegetated, acidophilic moss with high degree of water saturation, compacted crushed rock and gravel, and winter snow. The results showed that at a given site, there was no significant difference in radon emanation rates between various tailings covers and bare tailings. In particular, no increase In radon emanation rates from vegetated areas compared to bare tailings was observed. Radon emanation rates varied spatially depending on tailings grain size, porosity, moisture content and on pressure and water table variations. The emanation rates were higher for tailings with low water contents compared to those for wet and moss covered tailings

  20. Stylus type MEMS texture sensor covered with corrugated diaphragm

    Science.gov (United States)

    Tsukamoto, Takashiro; Asao, Hideaki; Tanaka, Shuji

    2017-09-01

    In this paper, a stylus type MEMS texture sensor covered with a corrugated palylene diaphragm, which prevent debris from jamming into the sensor without significant degradation of sensitivity and bandwidth, was reported. A new fabrication process using a lost-foil method to make the corrugated diaphragm on a 3-axis piezoresistive force sensor at wafer level has been developed. The texture sensor could detect the surface microstructure as small as about 10 \

  1. Water Quality Impacts of Cover Crop/Manure Management Systems

    OpenAIRE

    Kern, James Donald

    1997-01-01

    Crop production, soil system, water quality, and economic impacts of four corn silage production systems were compared through a field study including 16 plots (4 replications of each treatment). Systems included a rye cover crop and application of liquid dairy manure in the spring and fall. The four management systems were: 1) traditional, 2) double- crop, 3) roll-down, and 4) undercut. In the fourth system, manure was applied below the soil surface during the ...

  2. Sharing programming resources between Bio* projects through remote procedure call and native call stack strategies.

    Science.gov (United States)

    Prins, Pjotr; Goto, Naohisa; Yates, Andrew; Gautier, Laurent; Willis, Scooter; Fields, Christopher; Katayama, Toshiaki

    2012-01-01

    Open-source software (OSS) encourages computer programmers to reuse software components written by others. In evolutionary bioinformatics, OSS comes in a broad range of programming languages, including C/C++, Perl, Python, Ruby, Java, and R. To avoid writing the same functionality multiple times for different languages, it is possible to share components by bridging computer languages and Bio* projects, such as BioPerl, Biopython, BioRuby, BioJava, and R/Bioconductor. In this chapter, we compare the two principal approaches for sharing software between different programming languages: either by remote procedure call (RPC) or by sharing a local call stack. RPC provides a language-independent protocol over a network interface; examples are RSOAP and Rserve. The local call stack provides a between-language mapping not over the network interface, but directly in computer memory; examples are R bindings, RPy, and languages sharing the Java Virtual Machine stack. This functionality provides strategies for sharing of software between Bio* projects, which can be exploited more often. Here, we present cross-language examples for sequence translation, and measure throughput of the different options. We compare calling into R through native R, RSOAP, Rserve, and RPy interfaces, with the performance of native BioPerl, Biopython, BioJava, and BioRuby implementations, and with call stack bindings to BioJava and the European Molecular Biology Open Software Suite. In general, call stack approaches outperform native Bio* implementations and these, in turn, outperform RPC-based approaches. To test and compare strategies, we provide a downloadable BioNode image with all examples, tools, and libraries included. The BioNode image can be run on VirtualBox-supported operating systems, including Windows, OSX, and Linux.

  3. Call Duration Characteristics based on Customers Location

    Directory of Open Access Journals (Sweden)

    Žvinys Karolis

    2014-05-01

    Full Text Available Nowadays a lot of different researches are performed based on call duration distributions (CDD analysis. However, the majority of studies are linked with social relationships between the people. Therefore the scarcity of information, how the call duration is associated with a user's location, is appreciable. The goal of this paper is to reveal the ties between user's voice call duration and the location of call. For this reason we analyzed more than 5 million calls from real mobile network, which were made over the base stations located in rural areas, roads, small towns, business and entertainment centers, residential districts. According to these site types CDD’s and characteristic features for call durations are given and discussed. Submitted analysis presents the users habits and behavior as a group (not an individual. The research showed that CDD’s of customers being them in different locations are not equal. It has been found that users at entertainment, business centers are tend to talk much shortly, than people being at home. Even more CDD can be distorted strongly, when machinery calls are evaluated. Hence to apply a common CDD for a whole network it is not recommended. The study also deals with specific parameters of call duration for distinguished user groups, the influence of network technology for call duration is considered.

  4. Estimating solar resources in Mexico using cloud cover data

    Energy Technology Data Exchange (ETDEWEB)

    Renne, David; George, Ray; Brady, Liz; Marion, Bill [National Renewable Energy Laboratory, Colorado (United States); Estrada Cajigal, Vicente [Cuernavaca, Morelos (Mexico)

    2000-07-01

    This paper presents the results of applying the National Renewable Energy Laboratory's (NREL) Climatological Solar Radiation (CSR) model to Mexico to develop solar resource data. A major input to the CSR model is a worldwide surface and satellite-derived cloud cover database, called the Real Time Nephanalysis (RTNEPH). The RTNEPH is developed by the U.S. Air Force and distributed by the U.S. National Climatic Data Center. The RTNEPH combines routine ground-based cloud cover observations made every three hours at national weather centers throughout the world with satellite-derived cloud cover information developed from polar orbiting weather satellites. The data are geospatially digitized so that multilayerd cloud cover information is available on a grid of approximately 40-km to a side. The development of this database is an ongoing project that now covers more than twenty years of observations. For the North America analysis (including Mexico) we used an 8-year summarized histogram of the RTNEPH that provides monthly average cloud cover information for the period 1985-1992. The CSR model also accounts for attenuation of the solar beam due to aerosols, atmospheric trace gases, and water vapor. The CSR model outputs monthly average direct normal, global horizontal and diffuse solar information for each of the 40-km grid cells. From this information it is also possible to produce solar resource estimates for various solar collector types and orientations, such as flat plate collectors oriented at latitude tilt, or concentrating solar power collectors. Model results are displayed using Geographic Information System software. CSR model results for Mexico are presented here, along with a discussion of earlier solar resource assessment studies for Mexico, where both modeling approaches and measurement analyses have been used. [Spanish] Este articulo presenta los resultados de aplicar el modelo Radiacion Solar Climatologica CSR del NREL (National Renewable Energy

  5. Quantifying the Effects of Historical Land Cover Conversion Uncertainty on Global Carbon and Climate Estimates

    Science.gov (United States)

    Di Vittorio, A. V.; Mao, J.; Shi, X.; Chini, L.; Hurtt, G.; Collins, W. D.

    2018-01-01

    Previous studies have examined land use change as a driver of global change, but the translation of land use change into land cover conversion has been largely unconstrained. Here we quantify the effects of land cover conversion uncertainty on the global carbon and climate system using the integrated Earth System Model. Our experiments use identical land use change data and vary land cover conversions to quantify associated uncertainty in carbon and climate estimates. Land cover conversion uncertainty is large, constitutes a 5 ppmv range in estimated atmospheric CO2 in 2004, and generates carbon uncertainty that is equivalent to 80% of the net effects of CO2 and climate and 124% of the effects of nitrogen deposition during 1850-2004. Additionally, land cover uncertainty generates differences in local surface temperature of over 1°C. We conclude that future studies addressing land use, carbon, and climate need to constrain and reduce land cover conversion uncertainties.

  6. Minimal families of curves on surfaces

    KAUST Repository

    Lubbes, Niels

    2014-01-01

    A minimal family of curves on an embedded surface is defined as a 1-dimensional family of rational curves of minimal degree, which cover the surface. We classify such minimal families using constructive methods. This allows us to compute the minimal

  7. A dataset mapping the potential biophysical effects of vegetation cover change

    Science.gov (United States)

    Duveiller, Gregory; Hooker, Josh; Cescatti, Alessandro

    2018-02-01

    Changing the vegetation cover of the Earth has impacts on the biophysical properties of the surface and ultimately on the local climate. Depending on the specific type of vegetation change and on the background climate, the resulting competing biophysical processes can have a net warming or cooling effect, which can further vary both spatially and seasonally. Due to uncertain climate impacts and the lack of robust observations, biophysical effects are not yet considered in land-based climate policies. Here we present a dataset based on satellite remote sensing observations that provides the potential changes i) of the full surface energy balance, ii) at global scale, and iii) for multiple vegetation transitions, as would now be required for the comprehensive evaluation of land based mitigation plans. We anticipate that this dataset will provide valuable information to benchmark Earth system models, to assess future scenarios of land cover change and to develop the monitoring, reporting and verification guidelines required for the implementation of mitigation plans that account for biophysical land processes.

  8. Nonlinear surface waves at ferrite-metamaterial waveguide structure

    Science.gov (United States)

    Hissi, Nour El Houda; Mokhtari, Bouchra; Eddeqaqi, Noureddine Cherkaoui; Shabat, Mohammed Musa; Atangana, Jacques

    2016-09-01

    A new ferrite slab made of a metamaterial (MTM), surrounded by a nonlinear cover cladding and a ferrite substrate, was shown to support unusual types of electromagnetic surface waves. We impose the boundary conditions to derive the dispersion relation and others necessary to formulate the proposed structure. We analyse the dispersion properties of the nonlinear surface waves and we calculate the associated propagation index and the film-cover interface nonlinearity. In the calculation, several sets of the permeability of the MTM are considered. Results show that the waves behaviour depends on the values of the permeability of the MTM, the thickness of the waveguide and the film-cover interface nonlinearity. It is also shown that the use of the singular solutions to the electric field equation allows to identify several new properties of surface waves which do not exist in conventional waveguide.

  9. Control of water infiltration into near surface LLW disposal units: Task report, A discussion

    International Nuclear Information System (INIS)

    Schulz, R.K.; Ridky, R.W.; O'Donnell, E.

    1988-03-01

    The principal pathway for water entry into LLW disposal units in the humid eastern United States is through their covers. Two types of sub-surface features that may be constructed to enhance run-off (surface or sub-surface run-off) and thus reduce percolation are the resistive layer barrier, and the conductive layer barrier. The resistive layer barrier is the compacted soil or compacted clay layer and depends on compaction of permeable porous material to obtain low flow rates. The conductive layer barrier is a special case of the capillary barrier. Use is made of the capillary barrier phenomenon not only to increase the moisture content above an interface but to divert water away from the waste. During such diversion the water is at all times at negative capillary potential or under tension in the flow layer. A very effective barrier system might be constructed by placing a resistive barrier over a conductive barrier. Such a system must fail if appreciable subsidence takes place. An alternate procedure called bioengineering management utilizes engineered features at the surface (as opposed to the subsurface) to ensure adequate run-off. The engineered features are combined with stressed vegetation, that is, vegetation in an overdraft condition, to control deep percolation. (59 refs., 10 figs.)

  10. Influence of Western Tibetan Plateau Summer Snow Cover on East Asian Summer Rainfall

    Science.gov (United States)

    Wang, Zhibiao; Wu, Renguang; Chen, Shangfeng; Huang, Gang; Liu, Ge; Zhu, Lihua

    2018-03-01

    The influence of boreal winter-spring eastern Tibetan Plateau snow anomalies on the East Asian summer rainfall variability has been the focus of previous studies. The present study documents the impacts of boreal summer western and southern Tibetan Plateau snow cover anomalies on summer rainfall over East Asia. Analysis shows that more snow cover in the western and southern Tibetan Plateau induces anomalous cooling in the overlying atmospheric column. The induced atmospheric circulation changes are different corresponding to more snow cover in the western and southern Tibetan Plateau. The atmospheric circulation changes accompanying the western Plateau snow cover anomalies are more obvious over the midlatitude Asia, whereas those corresponding to the southern Plateau snow cover anomalies are more prominent over the tropics. As such, the western and southern Tibetan Plateau snow cover anomalies influence the East Asian summer circulation and precipitation through different pathways. Nevertheless, the East Asian summer circulation and precipitation anomalies induced by the western and southern Plateau snow cover anomalies tend to display similar distribution so that they are more pronounced when the western and southern Plateau snow cover anomalies work in coherence. Analysis indicates that the summer snow cover anomalies over the Tibetan Plateau may be related to late spring snow anomalies due to the persistence. The late spring snow anomalies are related to an obvious wave train originating from the western North Atlantic that may be partly associated with sea surface temperature anomalies in the North Atlantic Ocean.

  11. High-resolution electron-energy-loss spectroscopy studies of clean and hydrogen-covered tungsten (100) surfaces

    International Nuclear Information System (INIS)

    Woods, J.P.

    1986-01-01

    High-resolution (10-meV FWHM) low-energy (≤ 100eV) electrons are scattered from the tungsten (100) surface. Electron-energy-loss spectroscopy (EELS) selection rules are utilized to identify vibrational modes of the surface tungsten atoms. A 36-meV mode is measured on the c(2 X 2) thermally reconstructed surface and is modeled as an overtone of the 18-meV mode at M in the surface Brillouin zone. The superstructure of the reconstructed surface allows this mode to be observed in specular scattering. The surface tungsten atoms return to their bulk lateral positions with saturated hydrogen (β 1 phase) adsorption; and a 26-meV mode identified is due to the perpendicular vibration of the surface tungsten layers. The clean-room temperature surface does not display either low-energy vibrations and the surface is modeled as disordered. The three β 1 phase hydrogen vibrations are observed and a new vibration at 118 meV is identified. The 118-meV cross section displays characteristics of a parallel mode, but calculations show this assignment to be erroneous. There are two hydrogen atoms for each surface tungsten atom in the β 1 phase, and lattice-dynamical calculations show that the 118-meV mode is due to a hydrogen-zone edge vibration. The predicted breakdown of the parallel hydrogen vibration selection rule was not observed

  12. The effect of the cover and landscape design of waste rock dumps and tailings ponds on the water balance

    International Nuclear Information System (INIS)

    Haehne, R.; Eckart, M.; Marski, R.; Wolf, J.

    1998-01-01

    The dimensioning of cover systems for waste rock dumps and tailings ponds requires the prognosis of the water balances. Site specific field experiments as well as additional modelling efforts are necessary. The cover system could be a simple recultivation layering or a storage systems or a complex multi-layer-system. Uncovered dumps show typical percolation rates between 30 and 60%. Storage cover systems reduce the percolation rate down to 15 to 35%. The evapotranspiration rate is influenced especially by exposition and vegetation. Specific features for the cover of tailings ponds include a very low surface slope and the of percolation rate below 10%. Therefore, multi-layer-systems are most suitable, also because it is characterized by very low drainage velocities of hypodermic runoffs. The resulting, but temporarily high moisture and almost standing water at the surface leads to extreme evapotranspiration rates and consequently to an increase of percolation. (orig.) [de

  13. VORTICAL MODEL OF THE WING COVERED WITH CONTINUOUSLY DISTRIBUTED CIRCULATION OF THE VORTICAL LAYER

    Directory of Open Access Journals (Sweden)

    B. L. Artamonov

    2014-01-01

    Full Text Available The linear vortical model ot the final scope of a wing is exsamined. It representis the flat rectangular spatial veil covered with continuously distributed vortical layer. Elements of digitization of a veil are the quadrangular panels laying on its surface. Method, algorithms and the program of calculation of three making vectors of inductive speed from any guided rectangular platform covered with a vortical layer are created. Its intensity linearly changes on the surface of a platform. The decision is received in elementary functions. The numerical way solves the task of a definition of the law of circulation of the attached whirlwinds in scope of a wing and calculation of its aerodynamic characteristics, being based on the accepted vortical model and a hypothesis of flat sections.

  14. Impairment of vascularization of the surface covering epithelium induces ischemia and promotes malignization: a new hypothesis of a possible mechanism of cancer pathogenesis.

    Science.gov (United States)

    Karseladze, A I

    2015-06-01

    To study the peculiarities of vascularization at the stromal-epithelial interface in different types of epithelia and their alterations in precancerous lesions. Peritumoral tissues of 310 patients, tissues of 180 healthy persons and of 50 human embryos and fetuses were used. Traditional histological as well as immunohistochemical methods have been used. The study reveals that the occurrence of blood capillaries in surface squamous epithelium is an ordinary event, both in healthy persons and in peritumoral regions of the patients with squamous cell carcinoma. Glandular epithelial coverings, as well as transitional epithelium, do not contain blood vessels. In squamous epithelium, only basal cells are in contact with the membrane and underlying stroma, the cells of the upper layer receiving nutrients through diffusion. Thus, the cells of squamous epithelium are more vulnerable to blood deficiency, since for instance in the pseudo-multilayered respiratory epithelium each cell is attached directly to the basal membrane and has more ample access to the blood supply. Metaplastic squamous epithelium has a markedly reduced vascularization and seems to be more sensitive to carcinogenic stimuli. High-grade dysplastic squamous epithelium and carcinoma in situ do not contain blood vessels. The process of redistribution of vascular network occurring at the interface of epithelial-stromal frontier plays an important role in maintaining the adequate metabolism of cells including those of epithelial covering. Impairment of this mechanism most probably promotes precancerous alterations.

  15. Nitrate-nitrogen losses through subsurface drainage under various agricultural land covers.

    Science.gov (United States)

    Qi, Zhiming; Helmers, Matthew J; Christianson, Reid D; Pederson, Carl H

    2011-01-01

    Nitrate-nitrogen (NO₃-N) loading to surface water bodies from subsurface drainage is an environmental concern in the midwestern United States. The objective of this study was to investigate the effect of various land covers on NO₃-N loss through subsurface drainage. Land-cover treatments included (i) conventional corn ( L.) (C) and soybean [ (L.) Merr.] (S); (ii) winter rye ( L.) cover crop before corn (rC) and before soybean (rS); (iii) kura clover ( M. Bieb.) as a living mulch for corn (kC); and (iv) perennial forage of orchardgrass ( L.) mixed with clovers (PF). In spring, total N uptake by aboveground biomass of rye in rC, rye in rS, kura clover in kC, and grasses in PF were 14.2, 31.8, 87.0, and 46.3 kg N ha, respectively. Effect of land covers on subsurface drainage was not significant. The NO₃-N loss was significantly lower for kC and PF than C and S treatments (p rye cover crop did not reduce NO₃-N loss, but NO₃-N concentration was significantly reduced in rC during March to June and in rS during July to November (p rye cover crop on NO-N loss reduction needs further investigation under conditions of different N rates, wider weather patterns, and fall tillage. by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. On the performance of capillary barriers as landfill cover

    Science.gov (United States)

    Kämpf, M.; Montenegro, H.

    Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m). In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

  17. On the performance of capillary barriers as landfill cover

    Directory of Open Access Journals (Sweden)

    M. Kämpf

    1997-01-01

    Full Text Available Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m. In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

  18. Selective covers for natural cooling devices

    International Nuclear Information System (INIS)

    Addeo, A.; Monza, E.; Peraldo, M.; Bartoli, B.; Coluzzi, B.; Silvestrini, V.; Troise, G.

    1978-01-01

    Extra-atmospheric space is practically a pure sink of radiation, and can be used as a nonconventional energy source. In previous papers it has been shown that surfaces with an emissivity matched with the atmospheric (8/13)μm ''transparency window'' (natural emitters) interact with cold space when exposed to clear sky at night, and undergo a sizable cooling effect. In this paper, starting from experimental results concerning the diurnal performances of natural emitters, the problem of their interaction with solar radiation is discussed, and the use is proposed of selective covers which shade the emitter from solar radiation, without preventing the interaction with cold space via emission of infra-red radiation. (author)

  19. A proof that Witten's open string theory gives a single cover of moduli space

    International Nuclear Information System (INIS)

    Zwiebach, B.; Massachusetts Inst. of Tech., Cambridge

    1991-01-01

    We show that Witten's open string diagrams are surfaces with metrics of minimal area under the condition that all nontrivial open Jordan curves be longer or equal to π. The minimal area property is used together with a mini-max problem to establish a new existence and uniqueness theorem for quadratic differentials in open Riemann surfaces with or without punctures on the boundaries. This theorem implies that the Feynman rules of open string theory give a single cover of the moduli of open Riemann surfaces. (orig.)

  20. Two step formation of metal aggregates by surface X-ray radiolysis under Langmuir monolayers: 2D followed by 3D growth

    Directory of Open Access Journals (Sweden)

    Smita Mukherjee

    2015-12-01

    Full Text Available In order to form a nanostructured metallic layer below a Langmuir monolayer, radiolysis synthesis was carried out in an adapted geometry that we call surface X-ray radiolysis. In this procedure, an X-ray beam produced by a synchrotron beamline intercepts the surface of an aqueous metal-ion solution covered by a Langmuir monolayer at an angle of incidence below the critical angle for total internal reflection. Underneath the organic layer, the X-ray beam induces the radiolytic synthesis of a nanostructured metal–organic layer whose ultrathin thickness is defined by the vertical X-ray penetration depth. We have shown that increasing the X-ray flux on the surface, which considerably enhances the kinetics of the silver layer formation, results in a second growth regime of silver nanocrystals. Here the formation of the oriented thin layer is followed by the appearance of a 3D powder of silver clusters.

  1. Mapping ground cover using hyperspectral remote sensing after the 2003 Simi and Old wildfires in southern California

    Science.gov (United States)

    Sarah A. Lewis; Leigh B. Lentile; Andrew T. Hudak; Peter R. Robichaud; Penelope Morgan; Michael J. Bobbitt

    2007-01-01

    Wildfire effects on the ground surface are indicative of the potential for post-fire watershed erosion response. Areas with remaining organic ground cover will likely experience less erosion than areas of complete ground cover combustion or exposed mineral soil. The Simi and Old fires burned ~67,000 ha in southern California in 2003. Burn severity indices calculated...

  2. Estimation of Surface Air Temperature Over Central and Eastern Eurasia from MODIS Land Surface Temperature

    Science.gov (United States)

    Shen, Suhung; Leptoukh, Gregory G.

    2011-01-01

    Surface air temperature (T(sub a)) is a critical variable in the energy and water cycle of the Earth.atmosphere system and is a key input element for hydrology and land surface models. This is a preliminary study to evaluate estimation of T(sub a) from satellite remotely sensed land surface temperature (T(sub s)) by using MODIS-Terra data over two Eurasia regions: northern China and fUSSR. High correlations are observed in both regions between station-measured T(sub a) and MODIS T(sub s). The relationships between the maximum T(sub a) and daytime T(sub s) depend significantly on land cover types, but the minimum T(sub a) and nighttime T(sub s) have little dependence on the land cover types. The largest difference between maximum T(sub a) and daytime T(sub s) appears over the barren and sparsely vegetated area during the summer time. Using a linear regression method, the daily maximum T(sub a) were estimated from 1 km resolution MODIS T(sub s) under clear-sky conditions with coefficients calculated based on land cover types, while the minimum T(sub a) were estimated without considering land cover types. The uncertainty, mean absolute error (MAE), of the estimated maximum T(sub a) varies from 2.4 C over closed shrublands to 3.2 C over grasslands, and the MAE of the estimated minimum Ta is about 3.0 C.

  3. Can "YouTube" help students in learning surface anatomy?

    Science.gov (United States)

    Azer, Samy A

    2012-07-01

    In a problem-based learning curriculum, most medical students research the Internet for information for their "learning issues." Internet sites such as "YouTube" have become a useful resource for information. This study aimed at assessing YouTube videos covering surface anatomy. A search of YouTube was conducted from November 8 to 30, 2010 using research terms "surface anatomy," "anatomy body painting," "living anatomy," "bone landmarks," and "dermatomes" for surface anatomy-related videos. Only relevant video clips in the English language were identified and related URL recorded. For each videotape the following information were collected: title, authors, duration, number of viewers, posted comments, and total number of days on YouTube. The data were statistically analyzed and videos were grouped into educationally useful and non-useful videos on the basis of major and minor criteria covering technical, content, authority, and pedagogy parameters. A total of 235 YouTube videos were screened and 57 were found to have relevant information to surface anatomy. Analysis revealed that 15 (27%) of the videos provided useful information on surface anatomy. These videos scored (mean ± SD, 14.0 ± 0.7) and mainly covered surface anatomy of the shoulder, knee, muscles of the back, leg, and ankle, carotid artery, dermatomes, and anatomical positions. The other 42 (73%) videos were not useful educationally, scoring (mean ± SD, 7.4 ± 1.8). The total viewers of all videos were 1,058,634. Useful videos were viewed by 497,925 (47% of total viewers). The total viewership per day was 750 for useful videos and 652 for non-useful videos. No video clips covering surface anatomy of the head and neck, blood vessels and nerves of upper and lower limbs, chest and abdominal organs/structures were found. Currently, YouTube is an inadequate source of information for learning surface anatomy. More work is needed from medical schools and educators to add useful videos on You

  4. Assessing the impact of climate variability on catchment water balance and vegetation cover

    Directory of Open Access Journals (Sweden)

    X. Xu

    2012-01-01

    Full Text Available Understanding the interactions among climate, vegetation cover and the water cycle lies at the heart of the study of watershed ecohydrology. Recently, considerable attention is being paid to the effect of climate variability on catchment water balance and also associated vegetation cover. In this paper, we investigate the general pattern of long-term water balance and vegetation cover (as reflected by fPAR among 193 study catchments in Australia through statistical analysis. We then employ the elasticity analysis approach for quantifying the effects of climate variability on hydrologic partitioning (including total, surface and subsurface runoff and on vegetation cover (including total, woody and non-woody vegetation cover. Based on the results of statistical analysis, we conclude that annual runoff (R, evapotranspiration (E and runoff coefficient (R/P increase with vegetation cover for catchments in which woody vegetation is dominant and annual precipitation is relatively high. Control of water available on annual evapotranspiration in non-woody dominated catchments is relatively stronger compared to woody dominated ones. The ratio of subsurface runoff to total runoff (Rg/R also increases with woody vegetation cover. Through the elasticity analysis of catchment runoff, it is shown that precipitation (P in current year is the most important factor affecting the change in annual total runoff (R, surface runoff (Rs and subsurface runoff (Rg. The significance of other controlling factors is in the order of annual precipitation in previous years (P−1 and P−2, which represents the net effect of soil moisture and annual mean temperature (T in current year. Change of P by +1% causes a +3.35% change of R, a +3.47% change of Rs and a +2.89% change of

  5. INFLUENCE OF DIVIDING COVERINGS ON QUALITY OF CASTINGS AT MOLDING OF ALUMINUM ALLOYS UNDER PRESSURE

    Directory of Open Access Journals (Sweden)

    A. A. Pivovarchik

    2014-01-01

    Full Text Available The results of researches on influence of separating coverings on such properties of castings as corrosion resistance, roughness of cast surface, casting density are given in article.

  6. Wave Equation Inversion of Skeletonized SurfaceWaves

    KAUST Repository

    Zhang, Zhendong; Liu, Yike; Schuster, Gerard T.

    2015-01-01

    We present a surface-wave inversion method that inverts for the S-wave velocity from the Rayleigh dispersion curve for the fundamental-mode. We call this wave equation inversion of skeletonized surface waves because the dispersion curve

  7. Care and Calls

    DEFF Research Database (Denmark)

    Paasch, Bettina Sletten

    on the enactment of care but also on patient safety. Nurses working in various hospital departments have developed different strategies for handling mobile phone calls when with a patient. Additional research into the ways nurses successfully or unsuccessfully enact care and ensure patient safety when they answer......In Danish hospitals, nurses have been equipped with a mobile work phone to improve their availability and efficiency. On the phones nurses receive internal and external phone conversations, patient calls, and alarms from electronic surveillance equipment. For safety reasons the phones cannot...... be switched off or silenced; they consequently ring during all activities and also during interactions with patients. A possible tension thus arises when nurses have to be both caring and sensitive towards the patient and simultaneously be efficient and available and answer their phone. The present paper...

  8. Do market participants learn from conference calls?

    NARCIS (Netherlands)

    Roelofsen, E.; Verbeeten, F.; Mertens, G.

    2014-01-01

    We examine whether market participants learn from the information that is disseminated during the Q-and-A section of conference calls. Specifically, we investigate whether stock prices react to information on intangible assets provided during conference calls, and whether conference calls

  9. Upright nanopyramid structured cover glass with light harvesting and self-cleaning effects for solar cell applications

    International Nuclear Information System (INIS)

    Amalathas, Amalraj Peter; Alkaisi, Maan M

    2016-01-01

    In this paper, we demonstrate the effect of upright nanopyramid (UNP) structured cover glass with light harvesting and self-cleaning functions on the device performance of monocrystalline Si solar cells. The UNP structures were fabricated on the surface of the glass substrate by simple, high throughput and low cost UV nanoimprint lithography, using a Si master mold with inverted nanopyramid (INP) structures. The diffuse transmittance and haze ratio values were significantly increased for UNP patterned glass, especially in the wavelength range 300–600 nm compared to the bare glass; this implies that antireflection and strong light scattering are due to the UNP structures. By replacing a bare cover glass with UNP patterned glass, the power conversion efficiency of the monocrystalline Si solar cell was substantially enhanced by about 10.97%; this is mainly due to the increased short-circuit current density J SC of 32.39 mA cm −2 compared to the reference cell with bare cover glass (i.e. J SC   =  31.60 mA cm −2 ). In addition, unlike the bare cover glass (i.e. θ CA ∼ 36°), the fluorinated UNP structured cover glass exhibited a hydrophobic surface with a water contact angle ( θ CA ) of ∼132° and excellent self-cleaning of dust particles by rolling down water droplets. (paper)

  10. Mathematical modelling of water and gas transport in layered soil covers for coal ash deposit

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, M [Kemakta Consultants Co, Stockholm (SE); Rasmuson, A [Chalmers University of Technology, Goeteborg (SE). Dept. of Chemical Engineering Design

    1991-06-19

    In phase 1 of this study the design of soil covers for deposits of coal ash from energy production was studied with regard to various parameters like: climate, cover slope, hydraulic conductivity of tight layer and length of cover. One of the main results was the relatively large risk for total saturation up to the surface and overflow which may cause surface erosion problems. In the present study two theoretical cases are studied to further elucidate the problem. A case from the phase 1 study is used to illustrate the effect of increased infiltration. Calculations show that total saturation and thereby overflow is achieved when the infiltration is increased by 20% in March, but not when increased by 10% only. This shows that the margin in an acceptable case may be small. A cover treated in phase 1, where totally saturated conditions were obtained, was modified so that two decimeters of the one meter till in its bottom part were exchanged for a drainage layer. It is shown that the effect of this layer is large. A negative side-effect, however, is that gas flow may increase due to the lower saturation of the cover. Calculations were made for a real soil covered mine tailings deposit at Bersbo. This deposit was chosen mainly because it is the only well documented case in Sweden where soil covers are used for securing a deposit, but also because some contradictory results as compared to theory were obtained. Another topic studied in the present work was the influence of a heterogeneous clay layer. For example, a weak zone with a hydraulic conductivity of 10{sup -7} m/s (10{sup -9} m/s for the rest of the clay), covering 0.5 m x 0.5 m of 10 m in length and 5 m in width, will increase the flow through the bottom of the cover with almost 30%. The gas transport through the heterogeneous soil cover was also studied, showing about 5 times increased gas transport rate around the weak zone, but almost no difference about 1 m from the weak zone. (29 figs., 5 tabs., 27 refs.).

  11. Spectral response data for development of cool coloured tile coverings

    Science.gov (United States)

    Libbra, Antonio; Tarozzi, Luca; Muscio, Alberto; Corticelli, Mauro A.

    2011-03-01

    Most ancient or traditional buildings in Italy show steep-slope roofs covered by red clay tiles. As the rooms immediately below the roof are often inhabited in historical or densely urbanized centres, the combination of low solar reflectance of tile coverings and low thermal inertia of either wooden roof structures or sub-tile insulation panels makes summer overheating a major problem. The problem can be mitigated by using tiles coated with cool colours, that is colours with the same spectral response of clay tiles in the visible, but highly reflecting in the near infrared range, which includes more than half of solar radiation. Cool colours can yield the same visible aspect of common building surfaces, but higher solar reflectance. Studies aimed at developing cool colour tile coverings for traditional Italian buildings have been started. A few coating solutions with the typical red terracotta colour have been produced and tested in the laboratory, using easily available materials. The spectral response and the solar reflectance have been measured and compared with that of standard tiles.

  12. Progress in surface and membrane science

    CERN Document Server

    Cadenhead, D A

    1977-01-01

    Progress in Surface and Membrane Science, Volume 11 covers the advances in the study of surface and membrane science. The book discusses the quantum theory of surface phenomena; some fundamental aspects of electrocrystallization; and exoelectric emission. The text also describes the surface of titanium dioxide; and the prospects for atomic resolution electron microscopy in membranology. Chemists, physicists, and people involved in the electrochemical power laboratory will find the book useful.

  13. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2002-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.  

  14. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2002-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.

  15. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2001-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.

  16. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2001-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note: the number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.

  17. Debris cover increase as an essential factor determining evolution of the Djankuat Glacier in the Caucasus

    Science.gov (United States)

    Rezepkin, Alexey; Popovnin, Victor

    2013-04-01

    45-year-long direct monitoring of Djankuat Glacier mass and water balance revealed the continuous increase of its superficial debris cover. Its area was mapped 7 times since 1968 on a basis of photogrammetric surveys, showing more than three-fold increase from 0,104 to 0,344 km2, whereas its share in the entire glacier surface increased more than 4 times (from 3% to 13%); currently supraglacial moraine occupies 61% of the ablation area. Besides, 3 direct and complete areal surveys of debris thickness were carried out in 1983, 1994 and 2010. They consisted of 133-240 measurement points which were distributed either in checkmate order over uniform debris-covered parts of the snout or by transverse profiles across linear morainic ramparts. Procedure of measuring thickness with an accuracy of 1 cm was coming to till piercing down to ice surface with metallic rod or, when impossible, to manual excavations. Maximum detected point values reached 183 cm in 1983, 280 cm in 1994 and 245 cm in 2010, and average debris thickness turned out to increased more than twice during the monitoring period - 26, 39 and 54 cm, for correspondent surveys. Debris cover influence on liquid run-off was estimated by heat balance considerations, based both on records of AWSs, erected on clean and debris-covered ice surface, and on vertical temperature profiles within the lithogenic layer, demonstrating clearly the diurnal cycle attenuation with depth. Sub-debris ablation is higher than clean ice melting rate under a thin debris layer (2025 the debris cover will reduce hypsometrical lowering rate on the snout by 45% in the latter case. This lead to the assumption about the future role of debris mantle development in Djankuat Glacier evolution: it may become comparable with that exerted by climate change.

  18. Wild translation surfaces and infinite genus

    OpenAIRE

    Randecker, Anja

    2014-01-01

    The Gauss-Bonnet formula for classical translation surfaces relates the cone angle of the singularities (geometry) to the genus of the surface (topology). When considering more general translation surfaces, we observe so-called wild singularities for which the notion of cone angle is not applicable any more. In this article, we study whether there still exist relations between the geometry and the topology for translation surfaces with wild singularities. By considering short saddle connectio...

  19. Fractional Snow Cover Mapping by Artificial Neural Networks and Support Vector Machines

    Science.gov (United States)

    Çiftçi, B. B.; Kuter, S.; Akyürek, Z.; Weber, G.-W.

    2017-11-01

    Snow is an important land cover whose distribution over space and time plays a significant role in various environmental processes. Hence, snow cover mapping with high accuracy is necessary to have a real understanding for present and future climate, water cycle, and ecological changes. This study aims to investigate and compare the design and use of artificial neural networks (ANNs) and support vector machines (SVMs) algorithms for fractional snow cover (FSC) mapping from satellite data. ANN and SVM models with different model building settings are trained by using Moderate Resolution Imaging Spectroradiometer surface reflectance values of bands 1-7, normalized difference snow index and normalized difference vegetation index as predictor variables. Reference FSC maps are generated from higher spatial resolution Landsat ETM+ binary snow cover maps. Results on the independent test data set indicate that the developed ANN model with hyperbolic tangent transfer function in the output layer and the SVM model with radial basis function kernel produce high FSC mapping accuracies with the corresponding values of R = 0.93 and R = 0.92, respectively.

  20. Control of water infiltration into near surface LLW disposal units. Progress report on field experiments at a humid region site, Beltsville, Maryland: Volume 8

    International Nuclear Information System (INIS)

    Schulz, R.K.; Ridky, R.W.

    1995-04-01

    This study's objective is to assess means for controlling water infiltration through waste disposal unit covers in humid regions. Experimental work is being performed in large-scale lysimeters 21.34 m x 13.72 m x 3.05 m (75 ft x 45 ft x 10 ft) at Beltsville, Maryland. Results of the assessment are applicable to disposal of low-level radioactive waste (LLW), uranium mill tailings, hazardous waste, and sanitary landfills. Three kinds of waste disposal unit covers or barriers to water infiltration are being investigated: (1) resistive layer barrier, (2) conductive layer barrier, and (3) bioengineering management. The resistive layer barrier consists of compacted earthen material (e.g., clay). The conductive layer barrier consists of a conductive layer in conjunction with a capillary break. As long as unsaturated flow conditions are maintained, the conductive layer will wick water around the capillary break. Below-grade layered covers such as (1) and (2) will fail if there is appreciable subsidence of the cover, and remedial action for this kind of failure will be difficult. A surface cover, called bioengineering management, is meant to overcome this problem. The bioengineering management surface barrier is easily repairable if damaged by subsidence; therefore, it could be the system of choice under active subsidence conditions. The bioengineering management procedure also has been shown to be effective in dewatering saturated trenches and could be used for remedial action efforts. After cessation of subsidence, that procedure could be replaced by a resistive layer barrier or, perhaps even better, by a resistive layer barrier/conductive layer barrier system. The latter system would then give long-term effective protection against water entry into waste without institutional care

  1. Release of Phosphorus Forms from Cover Crop Residues in Agroecological No-Till Onion Production

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    Full Text Available ABSTRACT Cover crops grown alone or in association can take up different amounts of phosphorus (P from the soil and accumulate it in different P-forms in plant tissue. Cover crop residues with a higher content of readily decomposed forms may release P more quickly for the next onion crop. The aim of this study was to evaluate the release of P forms from residues of single and mixed cover crops in agroecological no-till onion (Allium cepa L. production. The experiment was conducted in Ituporanga, Santa Catarina (SC, Brazil, in an Inceptisol, with the following treatments: weeds, black oat (Avena sativa L., rye (Secale cereale L., oilseed radish (Raphanus sativus L., oilseed radish + black oat, and oilseed radish + rye. Cover crops were sown in April 2013. In July 2013, plant shoots were cut close to the soil surface and part of the material was placed in litterbags. The bags were placed on the soil surface and residues were collected at 0, 15, and 45 days after deposition (DAD. Residues were dried and ground and P in the plant tissue was determined through chemical fractionation. The release of P contained in the tissue of cover crops depends not only on total P content in the tissue, but also on the accumulation of P forms and the quality of the residue in decomposition. The highest accumulation of P in cover crops occurred in the soluble inorganic P fraction, which is the fraction of fastest release in plants. Black oat had the highest initial release rate of soluble inorganic P, which became equal to the release rate of other cover crop residues at 45 DAD. Weeds released only half the amount of soluble inorganic P in the same period, despite accumulating a considerable amount of P in their biomass. The mixtures of oilseed radish + rye and oilseed radish + black oat showed higher release of P associated with RNA at 45 DAD in comparison to the single treatments.

  2. Telephone calls by individuals with cancer.

    Science.gov (United States)

    Flannery, Marie; McAndrews, Leanne; Stein, Karen F

    2013-09-01

    To describe symptom type and reporting patterns found in spontaneously initiated telephone calls placed to an ambulatory cancer center practice. Retrospective, descriptive. Adult hematology oncology cancer center. 563 individuals with a wide range of oncology diagnoses who initiated 1,229 telephone calls to report symptoms. Raw data were extracted from telephone forms using a data collection sheet with 23 variables obtained for each phone call, using pre-established coding criteria. A literature-based, investigator-developed instrument was used for the coding criteria and selection of which variables to extract. Symptom reporting, telephone calls, pain, and symptoms. A total of 2,378 symptoms were reported by telephone during the four months. At least 10% of the sample reported pain (38%), fatigue (16%), nausea (16%), swelling (12%), diarrhea (12%), dyspnea (10%), and anorexia (10%). The modal response was to call only one time and to report only one symptom (55%). Pain emerged as the symptom that most often prompted an individual to pick up the telephone and call. Although variation was seen in symptom reporting, an interesting pattern emerged with an individual reporting on a solitary symptom in a single telephone call. The emergence of pain as the primary symptom reported by telephone prompted educational efforts for both in-person clinic visit management of pain and prioritizing nursing education and protocol management of pain reported by telephone. Report of symptoms by telephone can provide nurses unique insight into patient-centered needs. Although pain has been an important focus of education and research for decades, it remains a priority for individuals with cancer. A wide range in symptom reporting by telephone was evident.

  3. Green Infrastructure and Watershed-Scale Hydrology in a Mixed Land Cover System

    Science.gov (United States)

    Hoghooghi, N.; Golden, H. E.; Bledsoe, B. P.

    2017-12-01

    Urbanization results in replacement of pervious areas (e.g., vegetation, topsoil) with impervious surfaces such as roads, roofs, and parking lots, which cause reductions in interception, evapotranspiration, and infiltration, and increases in surface runoff (overland flow) and pollutant loads and concentrations. Research on the effectiveness of different Green Infrastructure (GI), or Low Impact Development (LID), practices to reduce these negative impacts on stream flow and water quality has been mostly focused at the local scale (e.g., plots, small catchments). However, limited research has considered the broader-scale effects of LID, such as how LID practices influence water quantity, nutrient removal, and aquatic ecosystems at watershed scales, particularly in mixed land cover and land use systems. We use the Visualizing Ecosystem Land Management Assessments (VELMA) model to evaluate the effects of different LID practices on daily and long-term watershed-scale hydrology, including infiltration surface runoff. We focus on Shayler Crossing (SHC) watershed, a mixed land cover (61% urban, 24% agriculture, 15% forest) subwatershed of the East Fork Little Miami River watershed, Ohio, United States, with a drainage area of 0.94 km2. The model was calibrated to daily stream flow at the outlet of SHC watershed from 2009 to 2010 and was applied to evaluate diverse distributions (at 25% to 100% implementation levels) and types (e.g., pervious pavement and rain gardens) of LID across the watershed. Results show reduced surface water runoff and higher rates of infiltration concomitant with increasing LID implementation levels; however, this response varies between different LID practices. The highest magnitude response in streamflow at the watershed outlet is evident when a combination of LID practices is applied. The combined scenarios elucidate that the diverse watershed-scale hydrological responses of LID practices depend primarily on the type and extent of the implemented

  4. Cover Crops for Managing Stream Water Quantity and Improving Stream Water Quality of Non-Tile Drained Paired Watersheds

    OpenAIRE

    Gurbir Singh; Jon E. Schoonover; Karl W. J. Williard

    2018-01-01

    In the Midwestern United States, cover crops are being promoted as a best management practice for managing nutrient and sediment losses from agricultural fields through surface and subsurface water movement. To date, the water quality benefits of cover crops have been inferred primarily from plot scale studies. This project is one of the first to analyze the impacts of cover crops on stream water quality at the watershed scale. The objective of this research was to evaluate nitrogen, phosphor...

  5. Outsourcing an Effective Postdischarge Call Program

    Science.gov (United States)

    Meek, Kevin L.; Williams, Paula; Unterschuetz, Caryn J.

    2018-01-01

    To improve patient satisfaction ratings and decrease readmissions, many organizations utilize internal staff to complete postdischarge calls to recently released patients. Developing, implementing, monitoring, and sustaining an effective call program can be challenging and have eluded some of the renowned medical centers in the country. Using collaboration with an outsourced vendor to bring state-of-the-art call technology and staffed with specially trained callers, health systems can achieve elevated levels of engagement and satisfaction for their patients postdischarge. PMID:29494453

  6. Calling to Nursing: Concept Analysis.

    Science.gov (United States)

    Emerson, Christie

    The aims of this article are (a) to analyze the concept of a calling as it relates nursing and (b) to develop a definition of calling to nursing with the detail and clarity needed to guide reliable and valid research. The classic steps described by Walker and Avant are used for the analysis. Literature from several disciplines is reviewed including vocational psychology, Christian career counseling, sociology, organizational management, and nursing. The analysis provides an operational definition of a calling to nursing and establishes 3 defining attributes of the concept: (a) a passionate intrinsic motivation or desire (perhaps with a religious component), (b) an aspiration to engage in nursing practice, as a means of fulfilling one's purpose in life, and (c) the desire to help others as one's purpose in life. Antecedents to the concept are personal introspection and cognitive awareness. Positive consequences to the concept are improved work meaningfulness, work engagement, career commitment, personal well-being, and satisfaction. Negative consequences of having a calling might include willingness to sacrifice well-being for work and problems with work-life balance. Following the concept analysis, philosophical assumptions, contextual factors, interdisciplinary work, research opportunities, and practice implications are discussed.

  7. MODIS Snow Cover Mapping Decision Tree Technique: Snow and Cloud Discrimination

    Science.gov (United States)

    Riggs, George A.; Hall, Dorothy K.

    2010-01-01

    Accurate mapping of snow cover continues to challenge cryospheric scientists and modelers. The Moderate-Resolution Imaging Spectroradiometer (MODIS) snow data products have been used since 2000 by many investigators to map and monitor snow cover extent for various applications. Users have reported on the utility of the products and also on problems encountered. Three problems or hindrances in the use of the MODIS snow data products that have been reported in the literature are: cloud obscuration, snow/cloud confusion, and snow omission errors in thin or sparse snow cover conditions. Implementation of the MODIS snow algorithm in a decision tree technique using surface reflectance input to mitigate those problems is being investigated. The objective of this work is to use a decision tree structure for the snow algorithm. This should alleviate snow/cloud confusion and omission errors and provide a snow map with classes that convey information on how snow was detected, e.g. snow under clear sky, snow tinder cloud, to enable users' flexibility in interpreting and deriving a snow map. Results of a snow cover decision tree algorithm are compared to the standard MODIS snow map and found to exhibit improved ability to alleviate snow/cloud confusion in some situations allowing up to about 5% increase in mapped snow cover extent, thus accuracy, in some scenes.

  8. Hydrogen evolution on Au(111) covered with submonolayers of Pd

    DEFF Research Database (Denmark)

    Björketun, Mårten; Karlberg, Gustav; Rossmeisl, Jan

    2011-01-01

    A theoretical investigation of electrochemical hydrogen evolution on Au(111) covered with submonolayers of Pd is presented. The size and shape of monoatomically high Pd islands formed on the Au(111) surface are determined using Monte Carlo simulations, for Pd coverages varying from 0.02 to 0.95 ML....... The energetics of adsorption and desorption of hydrogen on/from different types of sites on the Pd-Au(111) surface are assessed by means of density functional theory calculations combined with thermodynamic modeling. Based on the density functional and Monte Carlo data, the hydrogen evolution activity...... is evaluated with a micro-kinetic model. The analysis reproduces measured Pd-coverage-dependent activities for Pd submonolayers exceeding similar to 0.15 ML and enables the relative contributions from different types of electrocatalytically active sites to be determined. Finally, the implications of surface...

  9. Effects of modified surfaces produced at plasma-facing surface on hydrogen release behavior in the LHD

    Directory of Open Access Journals (Sweden)

    Y. Nobuta

    2017-08-01

    Full Text Available In the present study, an additional deuterium (D ion irradiation was performed against long-term samples mounted on the helical coil can and in the outer private region in the LHD during the 17th experimental campaign. Based on the release behavior of the D and hydrogen (H retained during the experimental campaign, the difference of release behavior at the top surface and in bulk of modified surfaces is discussed. Almost all samples on the helical coil can were erosion-dominant and some samples were covered with boron or carbon, while a very thick carbon films were formed in the outer private region. In the erosion-dominant area, the D desorbed at much lower temperatures compared to that of H retained during the LHD plasma operation. For the samples covered with boron, the D tended to desorb at lower temperatures compared to H. For the carbon deposition samples, the D desorbed at much higher temperatures compared to no deposition and boron-covered samples, which was very similar to that of H. The D retention capabilities at the top surface of carbon and boron films were 2–3 times higher than no deposition area. The results indicate that the retention and release behavior at the top surface of the modified layer can be different from that of bulk substrate material.

  10. The surface treatment lab team. From left to right : J Carosone, M Malabaila, JP Malivert (front row), M Thiebert and A Lasserre (back row)

    CERN Multimedia

    2001-01-01

    The surface treatment lab covers common metals with rarer ones through a process called electroplating. When electroplating is done, the piece of equipment made out of a common metal (like steel) is submerged in a solution which has the desired rare metal (like gold) dissolved in it. An electric current is then run through the solution to the common metal. The tiny rare metal particles follow the current and stick to the common metal when they reach it. It is then that the plating occcurs. All in all, a relatively simple process, but it can be potentially hazardous.

  11. Testing of newly developed functional surfaces under pure sliding conditions

    DEFF Research Database (Denmark)

    Godi, Alessandro; Mohaghegh, Kamran; Grønbæk, J.

    2013-01-01

    the surfaces in an industrial context. In this paper, a number of experimental tests were performed using a novel test rig, called axial sliding test, simulating the contact of surfaces under pure sliding conditions. The aim of the experiments is to evaluate the frictional behavior of a new typology...... of textured surfaces, the so-called multifunctional surfaces, characterized by a plateau area able to bear loads and a deterministic pattern of lubricant pockets. Six surface typologies, namely three multifunctional and three machined using classical processes, were chosen to slide against a mirror....... The results comparison showed clearly how employing multifunctional surfaces can reduce friction forces up to 50 % at high normal loads compared to regularly ground or turned surfaces. Friction coefficients approximately equal to 0.12 were found for classically machined surfaces, whereas the values were 0...

  12. Satellite altimetry in sea ice regions - detecting open water for estimating sea surface heights

    Science.gov (United States)

    Müller, Felix L.; Dettmering, Denise; Bosch, Wolfgang

    2017-04-01

    The Greenland Sea and the Farm Strait are transporting sea ice from the central Arctic ocean southwards. They are covered by a dynamic changing sea ice layer with significant influences on the Earth climate system. Between the sea ice there exist various sized open water areas known as leads, straight lined open water areas, and polynyas exhibiting a circular shape. Identifying these leads by satellite altimetry enables the extraction of sea surface height information. Analyzing the radar echoes, also called waveforms, provides information on the surface backscatter characteristics. For example waveforms reflected by calm water have a very narrow and single-peaked shape. Waveforms reflected by sea ice show more variability due to diffuse scattering. Here we analyze altimeter waveforms from different conventional pulse-limited satellite altimeters to separate open water and sea ice waveforms. An unsupervised classification approach employing partitional clustering algorithms such as K-medoids and memory-based classification methods such as K-nearest neighbor is used. The classification is based on six parameters derived from the waveform's shape, for example the maximum power or the peak's width. The open-water detection is quantitatively compared to SAR images processed while accounting for sea ice motion. The classification results are used to derive information about the temporal evolution of sea ice extent and sea surface heights. They allow to provide evidence on climate change relevant influences as for example Arctic sea level rise due to enhanced melting rates of Greenland's glaciers and an increasing fresh water influx into the Arctic ocean. Additionally, the sea ice cover extent analyzed over a long-time period provides an important indicator for a globally changing climate system.

  13. Mostly surfaces

    CERN Document Server

    Schwartz, Richard Evan

    2011-01-01

    This book presents a number of topics related to surfaces, such as Euclidean, spherical and hyperbolic geometry, the fundamental group, universal covering surfaces, Riemannian manifolds, the Gauss-Bonnet Theorem, and the Riemann mapping theorem. The main idea is to get to some interesting mathematics without too much formality. The book also includes some material only tangentially related to surfaces, such as the Cauchy Rigidity Theorem, the Dehn Dissection Theorem, and the Banach-Tarski Theorem. The goal of the book is to present a tapestry of ideas from various areas of mathematics in a clear and rigorous yet informal and friendly way. Prerequisites include undergraduate courses in real analysis and in linear algebra, and some knowledge of complex analysis.

  14. Classification of surface types using SIR-C/X-SAR, Mount Everest Area, Tibet

    Science.gov (United States)

    Albright, Thomas P.; Painter, Thomas H.; Roberts, Dar A.; Shi, Jiancheng; Dozier, Jeff; Fielding, Eric

    1998-01-01

    Imaging radar is a promising tool for mapping snow and ice cover in alpine regions. It combines a high-resolution, day or night, all-weather imaging capability with sensitivity to hydrologic and climatic snow and ice parameters. We use the spaceborne imaging radar-C/X-band synthetic aperture radar (SIR-C/X-SAR) to map snow and glacial ice on the rugged north slope of Mount Everest. From interferometrically derived digital elevation data, we compute the terrain calibration factor and cosine of the local illumination angle. We then process and terrain-correct radar data sets acquired on April 16, 1994. In addition to the spectral data, we include surface slope to improve discrimination among several surface types. These data sets are then used in a decision tree to generate an image classification. This method is successful in identifying and mapping scree/talus, dry snow, dry snow-covered glacier, wet snow-covered glacier, and rock-covered glacier, as corroborated by comparison with existing surface cover maps and other ancillary information. Application of the classification scheme to data acquired on October 7 of the same year yields accurate results for most surface types but underreports the extent of dry snow cover.

  15. estimation of land surface temperature of kaduna metropolis, nigeria

    African Journals Online (AJOL)

    Zaharaddeen et. al

    Land surface temperature can provide noteworthy information about the surface ... modelling the surface energy balance (Kalma, et al., 2008; ... Landsat, in addition some of the Landsat data have cloud cover and ..... The Impact Of Urban.

  16. EMERGENCY CALLS

    CERN Multimedia

    Medical Service

    2001-01-01

    IN URGENT NEED OF A DOCTOR GENEVA EMERGENCY SERVICES GENEVA AND VAUD 144 FIRE BRIGADE 118 POLICE 117 CERN FIREMEN 767-44-44 ANTI-POISONS CENTRE Open 24h/24h 01-251-51-51 Patient not fit to be moved, call family doctor, or: GP AT HOME, open 24h/24h 748-49-50 Association Of Geneva Doctors Emergency Doctors at home 07h-23h 322 20 20 Patient fit to be moved: HOPITAL CANTONAL CENTRAL 24 Micheli-du-Crest 372-33-11 ou 382-33-11 EMERGENCIES 382-33-11 ou 372-33-11 CHILDREN'S HOSPITAL 6 rue Willy-Donzé 372-33-11 MATERNITY 32 bvd.de la Cluse 382-68-16 ou 382-33-11 OPHTHALMOLOGY 22 Alcide Jentzer 382-33-11 ou 372-33-11 MEDICAL CENTRE CORNAVIN 1-3 rue du Jura 345 45 50 HOPITAL DE LA TOUR Meyrin EMERGENCIES 719-61-11 URGENCES PEDIATRIQUES 719-61-00 LA TOUR MEDICAL CENTRE 719-74-00 European Emergency Call 112 FRANCE EMERGENCY SERVICES 15 FIRE BRIGADE 18 POLICE 17 CERN FIREMEN AT HOME 00-41-22-767-44-44 ANTI-POISONS CENTRE Open 24h/24h 04-72-11-69-11 All doctors ...

  17. Coupled Environmental Processes in the Mojave Desert and Implications for ET Covers as Stable Landforms

    International Nuclear Information System (INIS)

    Shafer, D.; Young, M.; Zitzer, S.; McDonald, E.; Caldwell, T.

    2006-01-01

    Monolayer evapotranspiration (ET) covers are the baseline method for closure of disposal sites for low-level radioactive waste (LLW), mixed LLW, and transuranic (TRU) waste at the Nevada Test Site (NTS). The regulatory timeline is typically 1,000 years for LLW and 10,000 years for TRU waste. Covers for such waste have different technical considerations than those with shorter timelines because they are subject to environmental change for longer periods of time, and because the environmental processes are often coupled. To evaluate these changes, four analog sites (approximately 30, 1,000 to 2,000, 7,000 to 12,500, and 125,000 years in age) on the NTS were analyzed to address the early post-institutional control period (the youngest site), the 1,000-year compliance period for disposal of LLW, and the 10,000-year period for TRU waste. Tests included soil texture, structure, and morphology; surface soil infiltration and hydraulic conductivity; vegetation and faunal surveys; and literature reviews. Separate measurements were made in plant undercanopy and intercanopy areas. The results showed a progressive increase in silt and clay content of surface soils with age. Changes in soil texture and structure led to a fivefold decline in saturated hydraulic conductivity in intercanopy areas, but no change in undercanopies, which were subject to bioturbation. These changes may have been responsible for the reduction in total plant cover, most dramatically in intercanopy areas, primarily because more precipitation either runs off the site or is held nearer to the surface where plant roots are less common. The results suggest that covers may evolve over longer timeframes to stable landforms that minimize the need for active maintenance

  18. In Situ Nondestructive Analysis of Kalanchoe pinnata Leaf Surface Structure by Polarization-Modulation Infrared Reflection-Absorption Spectroscopy.

    Science.gov (United States)

    Hama, Tetsuya; Kouchi, Akira; Watanabe, Naoki; Enami, Shinichi; Shimoaka, Takafumi; Hasegawa, Takeshi

    2017-12-14

    The outermost surface of the leaves of land plants is covered with a lipid membrane called the cuticle that protects against various stress factors. Probing the molecular-level structure of the intact cuticle is highly desirable for understanding its multifunctional properties. We report the in situ characterization of the surface structure of Kalanchoe pinnata leaves using polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS). Without sample pretreatment, PM-IRRAS measures the IR spectra of the leaf cuticle of a potted K. pinnata plant. The peak position of the CH 2 -related modes shows that the cuticular waxes on the leaf surface are mainly crystalline, and the alkyl chains are highly packed in an all-trans zigzag conformation. The surface selection rule of PM-IRRAS revealed the average orientation of the cuticular molecules, as indicated by the positive and negative signals of the IR peaks. This unique property of PM-IRRAS revealed that the alkyl chains of the waxes and the main chains of polysaccharides are oriented almost perpendicular to the leaf surface. The nondestructive, background-free, and environmental gas-free nature of PM-IRRAS allows the structure and chemistry of the leaf cuticle to be studied directly in its native environment.

  19. Combining MOD10A1 and MYD10A1 Images For Snow Cover Area Monitoring

    Science.gov (United States)

    Tekeli, A. E.

    2008-12-01

    MOD10A1 and MYD10A1 daily snow cover maps at 500 m resolution are available from MODIS sensors on Terra and Aqua satellites. Aqua obtains the image of same region approximately three hours after Terra over Turkey region. MODIS is an optic sensor and cloud cover degrades the usability of derived snow cover maps. Moreover, spectral similarity between clouds and snow complicates their separability in visible imagery. Fortunately, dynamic behavior of clouds enables their discrimination from snow stationary on the surface. Combined use of MOD10A1 and MYD10A1 images mostly reduces the cloud cover present in one image alone and provides better representation of surface snow cover. Comparison of merged images with in situ data indicated higher hit ratios. The individual comparison of MOD10A1 and MYD10A1 images with ground data each yielded 31% hit ratio whereas, the merged images provided 38%. One-day shifts in comparisons increased hit ratios to 52 % and 46% whereas and two-day shifts gave 77 % and 79 % for MOD10A1 and MYD10A1 respectively. Merged maps yielded 54% and 83% for one and two day shifts. The improvement provided by the merging technique is found to be 7% for the present day, 7 % for one- day and 5% for two-day shifts for the whole season. Monthly decomposition resulted 25% improvement as the maximum. The snow cover product obtained by merging Terra and Aqua satellites provided higher hit ratios, as expected.

  20. 77 FR 48733 - Transitional Program for Covered Business Method Patents-Definitions of Covered Business Method...

    Science.gov (United States)

    2012-08-14

    ... Office 37 CFR Part 42 Transitional Program for Covered Business Method Patents--Definitions of Covered... Business Method Patents-- Definitions of Covered Business Method Patent and Technological Invention AGENCY... forth in detail the definitions of the terms ``covered business method patent'' and ``technological...

  1. Performance assessment of a single-layer moisture store-and-release cover system at a mine waste rock pile in a seasonally humid region (Nova Scotia, Canada).

    Science.gov (United States)

    Power, Christopher; Ramasamy, Murugan; Mkandawire, Martin

    2018-03-03

    Cover systems are commonly applied to mine waste rock piles (WRPs) to control acid mine drainage (AMD). Single-layer covers utilize the moisture "store-and-release" concept to first store and then release moisture back to the atmosphere via evapotranspiration. Although more commonly used in semi-arid and arid climates, store-and-release covers remain an attractive option in humid climates due to the low cost and relative simplicity of installation. However, knowledge of their performance in these climates is limited. The objective of this study was to assess the performance of moisture store-and-release covers at full-scale WRPs located in humid climates. This cover type was installed at a WRP in Nova Scotia, Canada, alongside state-of-the-art monitoring instrumentation. Field monitoring was conducted over 5 years to assess key components such as meteorological conditions, cover material water dynamics, net percolation, surface runoff, pore-gas, environmental receptor water quality, landform stability and vegetation. Water balances indicate small reductions in water influx to the waste rock (i.e., 34 to 28% of precipitation) with the diminished AMD release also apparent by small improvements in groundwater quality (increase in pH, decrease in sulfate/metals). Surface water quality analysis and field observations of vegetative/aquatic life demonstrate significant improvements in the surface water receptor. The WRP landform is stable and the vegetative cover is thriving. This study has shown that while a simple store-and-release cover may not be a highly effective barrier to water infiltration in humid climates, it can be used to (i) eliminate contaminated surface water runoff, (ii) minimize AMD impacts to surface water receptor(s), (iii) maintain a stable landform, and (iv) provide a sustainable vegetative canopy.

  2. TPMG Northern California appointments and advice call center.

    Science.gov (United States)

    Conolly, Patricia; Levine, Leslie; Amaral, Debra J; Fireman, Bruce H; Driscoll, Tom

    2005-08-01

    Kaiser Permanente (KP) has been developing its use of call centers as a way to provide an expansive set of healthcare services to KP members efficiently and cost effectively. Since 1995, when The Permanente Medical Group (TPMG) began to consolidate primary care phone services into three physical call centers, the TPMG Appointments and Advice Call Center (AACC) has become the "front office" for primary care services across approximately 89% of Northern California. The AACC provides primary care phone service for approximately 3 million Kaiser Foundation Health Plan members in Northern California and responds to approximately 1 million calls per month across the three AACC sites. A database records each caller's identity as well as the day, time, and duration of each call; reason for calling; services provided to callers as a result of calls; and clinical outcomes of calls. We here summarize this information for the period 2000 through 2003.

  3. IDENTIFICATION OF LAND COVER IN THE PAST USING INFRARED IMAGES AT PRESENT

    Directory of Open Access Journals (Sweden)

    V. Šafář

    2012-07-01

    Full Text Available Czech landscape is an old residential area used by humans since ancient times. People have influenced it since their arrival and various activities in different periods create landscape layers called a palimpsest. Land Cover of one location could have changed several times. The most important reason is meandering and subsequent straightening of rivers, deforestation, relocation and change in soil layers. These changes in the past affected the present management and it is important to identify them. A suitable tool for the determination of different sites is remote sensing in the infrared spectrum, which monitors changes in the vegetation with the support of archival materials. After identifying the different places you can search the archival materials, how the land cover looked in the past. There have been used these archival materials: maps II. and III. military mapping, basic maps and other maps and historical orthophotomap. Czech Republic has a national archive of aerial photographs with aerial photographs from the thirties of the last century maintained by MGHO Dobruska. A comparative analysis of Land Cover shows the increases and decreases in agricultural land, changes in communication line elements, forest losses and increases, comparing the legal and actual status of the forest boundaries and their changes over time, changes in the built areas and links to the surrounding countryside. Land Cover of this study was created primarily with a visual interpretation of each area with their vectorization and assigning attributes to these areas and then comparing each of archival materials.

  4. Evolution of advertisement calls in African clawed frogs

    Science.gov (United States)

    Tobias, Martha L.; Evans, Ben J.; Kelley, Darcy B.

    2014-01-01

    Summary For most frogs, advertisement calls are essential for reproductive success, conveying information on species identity, male quality, sexual state and location. While the evolutionary divergence of call characters has been examined in a number of species, the relative impacts of genetic drift or natural and sexual selection remain unclear. Insights into the evolutionary trajectory of vocal signals can be gained by examining how advertisement calls vary in a phylogenetic context. Evolution by genetic drift would be supported if more closely related species express more similar songs. Conversely, a poor correlation between evolutionary history and song expression would suggest evolution shaped by natural or sexual selection. Here, we measure seven song characters in 20 described and two undescribed species of African clawed frogs (genera Xenopus and Silurana) and four populations of X. laevis. We identify three call types — click, burst and trill — that can be distinguished by click number, call rate and intensity modulation. A fourth type is biphasic, consisting of two of the above. Call types vary in complexity from the simplest, a click, to the most complex, a biphasic call. Maximum parsimony analysis of variation in call type suggests that the ancestral type was of intermediate complexity. Each call type evolved independently more than once and call type is typically not shared by closely related species. These results indicate that call type is homoplasious and has low phylogenetic signal. We conclude that the evolution of call type is not due to genetic drift, but is under selective pressure. PMID:24723737

  5. Porous Media and Immersed Boundary Hybrid-Modelling for Simulating Flow in Stone Cover-Layers

    DEFF Research Database (Denmark)

    Jensen, Bjarne; Liu, Xiaofeng; Christensen, Erik Damgaard

    In this paper we present a new numerical modelling approach for coastal and marine applications where a porous media conceptual model was combined with a free surface volume-of-fluid (VOF) model and an immersed boundary method (IBM). The immersed boundary model covers the method of describing....... In this paper, the model is applied to investigate two practical cases in terms of a cover layer of stones on a flat bed under oscillatory flow at different packing densities, and a rock toe structure at a breakwater....

  6. Triassico: A Sphere Positioning System for Surface Studies with IBA Techniques

    Science.gov (United States)

    Fontana, Cristiano L.; Doyle, Barney L.

    We propose here a novel device, called the Triassico, to microscopically study the entire surface of millimeter-sized spheres. The sphere dimensions can be as small as 1 mm, and the upper limit defined only by the power and by the mechanical characteristics of the motors used. Three motorized driving rods are arranged so an equilateral triangle is formed by the rod's axes, on such a triangle the sphere sits. Movement is achieved by rotating the rods with precise relative speeds and by exploiting the friction between the sphere and the rods surfaces. The sphere can be held in place by gravity or by an opposing trio of rods. By rotating the rods with specific relative angular velocities, a net torque can be exerted on the sphere which then rotates. No repositioning of the sphere or of the motors is needed to cover the full surface with the investigating tools. An algorithm was developed to position the sphere at any arbitrary polar and azimuthal angle. The algorithm minimizes the number of rotations needed by the rods, in order to efficiently select a particular position on the sphere surface. A prototype Triassico was developed for the National Ignition Facility, of the Lawrence Livermore National Laboratory (Livermore, California, USA), as a sphere manipulation apparatus for ion microbeam analysis at Sandia National Laboratories (Albuquerque, NM, USA) of Xe-doped DT inertial confinement fusion fuel spheres. Other applications span from samples orientation, ball bearing manufacturing, or jewelry.

  7. Twenty-four year record of Northern Hemisphere snow cover derived from passive microwave remote sensing

    Science.gov (United States)

    Armstrong, Richard L.; Brodzik, Mary Jo

    2003-04-01

    Snow cover is an important variable for climate and hydrologic models due to its effects on energy and moisture budgets. Seasonal snow can cover more than 50% of the Northern Hemisphere land surface during the winter resulting in snow cover being the land surface characteristic responsible for the largest annual and interannual differences in albedo. Passive microwave satellite remote sensing can augment measurements based on visible satellite data alone because of the ability to acquire data through most clouds or during darkness as well as to provide a measure of snow depth or water equivalent. It is now possible to monitor the global fluctuation of snow cover over a 24 year period using passive microwave data (Scanning Multichannel Microwave Radiometer (SMMR) 1978-1987 and Special Sensor Microwave/Imager (SSM/I), 1987-present). Evaluation of snow extent derived from passive microwave algorithms is presented through comparison with the NOAA Northern Hemisphere snow extent data. For the period 1978 to 2002, both passive microwave and visible data sets show a smiliar pattern of inter-annual variability, although the maximum snow extents derived from the microwave data are consistently less than those provided by the visible statellite data and the visible data typically show higher monthly variability. During shallow snow conditions of the early winter season microwave data consistently indicate less snow-covered area than the visible data. This underestimate of snow extent results from the fact that shallow snow cover (less than about 5.0 cm) does not provide a scattering signal of sufficient strength to be detected by the algorithms. As the snow cover continues to build during the months of January through March, as well as on into the melt season, agreement between the two data types continually improves. This occurs because as the snow becomes deeper and the layered structure more complex, the negative spectral gradient driving the passive microwave algorithm

  8. Covering folded shapes

    Directory of Open Access Journals (Sweden)

    Oswin Aichholzer

    2014-05-01

    Full Text Available Can folding a piece of paper flat make it larger? We explore whether a shape S must be scaled to cover a flat-folded copy of itself. We consider both single folds and arbitrary folds (continuous piecewise isometries \\(S\\to\\mathbb{R}^2\\. The underlying problem is motivated by computational origami, and is related to other covering and fixturing problems, such as Lebesgue's universal cover problem and force closure grasps. In addition to considering special shapes (squares, equilateral triangles, polygons and disks, we give upper and lower bounds on scale factors for single folds of convex objects and arbitrary folds of simply connected objects.

  9. Determining the Covering Factor of Compton-Thick Active Galactic Nuclei with NuSTAR

    Science.gov (United States)

    Brightman, M.; Balokovic, M.; Stern, D.; Arevalo, P.; Ballantyne, D. R.; Bauer, F. E.; Boggs, S. E.; Craig, W. W.; Christensen, F. E.; Zhang, W. W.

    2015-01-01

    The covering factor of Compton-thick (CT) obscuring material associated with the torus in active galactic nuclei (AGNs) is at present best understood through the fraction of sources exhibiting CT absorption along the line of sight (N(sub H) greater than 1.5 x 10(exp 24) cm(exp -2)) in the X-ray band, which reveals the average covering factor. Determining this CT fraction is difficult, however, due to the extreme obscuration. With its spectral coverage at hard X-rays (greater than 10 keV), Nuclear Spectroscopic Telescope Array (NuSTAR) is sensitive to the AGNs covering factor since Compton scattering of X-rays off optically thick material dominates at these energies. We present a spectral analysis of 10 AGNs observed with NuSTAR where the obscuring medium is optically thick to Compton scattering, so-called CT AGNs. We use the torus models of Brightman and Nandra that predict the X-ray spectrum from reprocessing in a torus and include the torus opening angle as a free parameter and aim to determine the covering factor of the CT gas in these sources individually. Across the sample we find mild to heavy CT columns, with N(sub H) measured from 10(exp 24) to 10(exp 26) cm(exp -2), and a wide range of covering factors, where individual measurements range from 0.2 to 0.9. We find that the covering factor, f(sub c), is a strongly decreasing function of the intrinsic 2-10 keV luminosity, L(sub X), where f(sub c) = (-0.41 +/- 0.13)log(sub 10)(L(sub X)/erg s(exp -1))+18.31 +/- 5.33, across more than two orders of magnitude in L(sub X) (10(exp 41.5) - 10(exp 44) erg s(exp -1)). The covering factors measured here agree well with the obscured fraction as a function of LX as determined by studies of local AGNs with L(sub X) greater than 10(exp 42.5) erg s(exp -1).

  10. Hysteresis of boiling for different tunnel-pore surfaces

    Directory of Open Access Journals (Sweden)

    Pastuszko Robert

    2015-01-01

    Full Text Available Analysis of boiling hysteresis on structured surfaces covered with perforated foil is proposed. Hysteresis is an adverse phenomenon, preventing high heat flux systems from thermal stabilization, characterized by a boiling curve variation at an increase and decrease of heat flux density. Experimental data were discussed for three kinds of enhanced surfaces: tunnel structures (TS, narrow tunnel structures (NTS and mini-fins covered with the copper wire net (NTS-L. The experiments were carried out with water, R-123 and FC-72 at atmospheric pressure. A detailed analysis of the measurement results identified several cases of type I, II and III for TS, NTS and NTS-L surfaces.

  11. A Surface Temperature Initiated Closure (STIC) for surface energy balance fluxes

    DEFF Research Database (Denmark)

    Mallick, Kaniska; Jarvis, Andrew J.; Boegh, Eva

    2014-01-01

    The use of Penman–Monteith (PM) equation in thermal remote sensing based surface energy balance modeling is not prevalent due to the unavailability of any direct method to integrate thermal data into the PM equation and due to the lack of physical models expressing the surface (or stomatal......) and boundary layer conductances (gS and gB) as a function of surface temperature. Here we demonstrate a new method that physically integrates the radiometric surface temperature (TS) into the PM equation for estimating the terrestrial surface energy balance fluxes (sensible heat, H and latent heat, λ......E). The method combines satellite TS data with standard energy balance closure models in order to derive a hybrid closure that does not require the specification of surface to atmosphere conductance terms. We call this the Surface Temperature Initiated Closure (STIC), which is formed by the simultaneous solution...

  12. Characteristics of the ancient tombs and application to cover design of a near-surface disposal facility : literature survey

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Beak; Lee, Ji Hoon; Park, Joo Wan; Kim, Chang Lak [Nuclear Environment Technology Institute, Taejeon (Korea, Republic of); Yang, Si Eun; Lee, Sun Bok [Seoul National University, Seoul (Korea, Republic of)

    2005-06-15

    To support the design concept and performance evaluation of the cover system for low- and intermediate-level radioactive waste(LILW) disposal facility, the pioneering study is conducted with the tomb of historical age. Research status of the art are followed and the characteristics of tomb cover are summarized based on the preservation of historical remains. Visiting the excavation site of historical tomb and communication with Korean archaeological society is required for the further understanding and for the extension of radioactive waste disposal research.

  13. LAND COVER CHANGE MONITORING OF TYPICAL FUNCTIONAL COMMUNITIES OF SICHUAN PROVINCE BASED ON ZY-3 DATA

    Directory of Open Access Journals (Sweden)

    G. M. Li

    2018-04-01

    Full Text Available According to the function, land space types are divided into key development areas, restricted development areas and forbidden development areas in Sichuan Province. This paper monitors and analyses the changes of land cover in different typical functional areas from 2010 to 2017, which based on ZY-3 high-score images data and combined with statistical yearbook and thematic data of Sichuan Province. The results show that: The land cover types of typical key development zones are mainly composed of cultivated land, forest land, garden land, and housing construction land, which accounts for the total area of land cover 87 %. The land cover types of typical restricted development zone mainly consists of forest land and grassland, which occupy 97.71 % of the total area of the surface coverage. The land cover types of the typical prohibition development zone mainly consist of forest land, grassland, desert and bared earth, which accounts for the total area of land cover 99.31 %.

  14. Land Cover Change Monitoring of Typical Functional Communities of Sichuan Province Based on ZY-3 Data

    Science.gov (United States)

    Li, G. M.; Li, S.; Ying, G. W.; Wu, X. P.

    2018-04-01

    According to the function, land space types are divided into key development areas, restricted development areas and forbidden development areas in Sichuan Province. This paper monitors and analyses the changes of land cover in different typical functional areas from 2010 to 2017, which based on ZY-3 high-score images data and combined with statistical yearbook and thematic data of Sichuan Province. The results show that: The land cover types of typical key development zones are mainly composed of cultivated land, forest land, garden land, and housing construction land, which accounts for the total area of land cover 87 %. The land cover types of typical restricted development zone mainly consists of forest land and grassland, which occupy 97.71 % of the total area of the surface coverage. The land cover types of the typical prohibition development zone mainly consist of forest land, grassland, desert and bared earth, which accounts for the total area of land cover 99.31 %.

  15. EXAMINING COMFORT PROPERTIES OF LEATHER and ARTIFICIAL LEATHER COVER MATERIALS

    Directory of Open Access Journals (Sweden)

    ÇETİN Münire Sibel

    2016-05-01

    Full Text Available The analysis and regulation of workplace, working instruments, the comfort of office chair, business environment (sound, lighting, climate, vibration, temperature, and humidity, work and break times, analysis and editing of the organization, are some of the topics of interest of ergonomics. Environmental impact and conditions have important role on the employee’s working comfortably and efficiently. Therefore these conditions need to be aligned to the human body nature. Unsuitable working conditions (noise, etc. cause additional load, which the human body endures, and this additional load reveals the signs of tiredness in the body. Even an office environment, unsuitable physical environment impairs health of workers and reduces the performance. Therefore, office climate, environmental factors such as lighting and noise must be harmonized with the employee’s body nature in all working environments. Seating comfort is one of the important factors affecting the performance of employees in the office environment. There are so many studies about chair dimensions and the disorders on human body which were caused by the inappropriate chair dimensions and sitting positions. However, there are a spot of studies about the surface of the chair and the discomfort caused by the chair cover and its negative performance effects. In this study, some results of seat cover analysis for the design of an ergonomic chair. Recently, ease of cleaning, low cost advantages caused the increasing of the use of artificial leather especially on the surface of the seat used in offices. The physical properties of natural leather and artificial leather were compared as the candidate covers to be used on the design of an ergonomic office chair.

  16. Finite translation surfaces with maximal number of translations

    OpenAIRE

    Schlage-Puchta, Jan-Christoph; Weitze-Schmithuesen, Gabriela

    2013-01-01

    The natural automorphism group of a translation surface is its group of translations. For finite translation surfaces of genus g > 1 the order of this group is naturally bounded in terms of g due to a Riemann-Hurwitz formula argument. In analogy with classical Hurwitz surfaces, we call surfaces which achieve the maximal bound Hurwitz translation surfaces. We study for which g there exist Hurwitz translation surfaces of genus g.

  17. Land cover and water yield: inference problems when comparing catchments with mixed land cover

    Directory of Open Access Journals (Sweden)

    A. I. J. M. van Dijk

    2012-09-01

    Full Text Available Controlled experiments provide strong evidence that changing land cover (e.g. deforestation or afforestation can affect mean catchment streamflow (Q. By contrast, a similarly strong influence has not been found in studies that interpret Q from multiple catchments with mixed land cover. One possible reason is that there are methodological issues with the way in which the Budyko framework was used in the latter type studies. We examined this using Q data observed in 278 Australian catchments and by making inferences from synthetic Q data simulated by a hydrological process model (the Australian Water Resources Assessment system Landscape model. The previous contrasting findings could be reproduced. In the synthetic experiment, the land cover influence was still present but not accurately detected with the Budyko- framework. Likely sources of interpretation bias demonstrated include: (i noise in land cover, precipitation and Q data; (ii additional catchment climate characteristics more important than land cover; and (iii covariance between Q and catchment attributes. These methodological issues caution against the use of a Budyko framework to quantify a land cover influence in Q data from mixed land-cover catchments. Importantly, however, our findings do not rule out that there may also be physical processes that modify the influence of land cover in mixed land-cover catchments. Process model simulations suggested that lateral water redistribution between vegetation types and recirculation of intercepted rainfall may be important.

  18. Generation and Assessment of Urban Land Cover Maps Using High-Resolution Multispectral Aerial Images

    DEFF Research Database (Denmark)

    Höhle, Joachim; Höhle, Michael

    2013-01-01

    a unique method for the automatic generation of urban land cover maps. In the present paper, imagery of a new medium-format aerial camera and advanced geoprocessing software are applied to derive normalized digital surface models and vegetation maps. These two intermediate products then become input...... to a tree structured classifier, which automatically derives land cover maps in 2D or 3D. We investigate the thematic accuracy of the produced land cover map by a class-wise stratified design and provide a method for deriving necessary sample sizes. Corresponding survey adjusted accuracy measures...... and their associated confidence intervals are used to adequately reflect uncertainty in the assessment based on the chosen sample size. Proof of concept for the method is given for an urban area in Switzerland. Here, the produced land cover map with six classes (building, wall and carport, road and parking lot, hedge...

  19. Armored Geomembrane Cover Engineering

    Directory of Open Access Journals (Sweden)

    Kevin Foye

    2011-06-01

    Full Text Available Geomembranes are an important component of modern engineered barriers to prevent the infiltration of stormwater and runoff into contaminated soil and rock as well as waste containment facilities—a function generally described as a geomembrane cover. This paper presents a case history involving a novel implementation of a geomembrane cover system. Due to this novelty, the design engineers needed to assemble from disparate sources the design criteria for the engineering of the cover. This paper discusses the design methodologies assembled by the engineering team. This information will aid engineers designing similar cover systems as well as environmental and public health professionals selecting site improvements that involve infiltration barriers.

  20. Agricultural land cover changes in metropolitan areas of Poland for the period 1990–2012

    Directory of Open Access Journals (Sweden)

    Nalej Marta

    2016-06-01

    Full Text Available Agricultural land covers more than half the area of metropolitan areas in Poland, and is therefore particularly prone to the influences of the processes associated with their development. The aim of the study was to analyse changes in agricultural land cover within the metropolitan areas of Poland for the years 1990–2012; and to capture their dynamics, types and directions. The percentage share of the total study area, for each of the forms of agricultural land cover and their changes were traced, with the spatial distribution of the changes also being determined. The results of the study show that in metropolitan areas, agricultural land cover is undergoing transformations that do not result in the loss of agricultural lands, or that involve a decrease in surface area due to their change into anthropogenic forms of land cover. The greatest transitions occurred between 2000 and 2006 and were observed in the outer zones of metropolitan areas.